moved

40 files changed, 5999 insertions, 0 deletions

diff --git a/2021/day01/day01 b/2021/day01/day01
new file mode 100755
index 0000000..8fb500a
--- /dev/null
+++ b/2021/day01/day01
diff --git a/2021/day01/day01.cpp b/2021/day01/day01.cpp
new file mode 100644
index 0000000..113f86d
--- /dev/null
+++ b/2021/day01/day01.cpp
@@ -0,0 +1,52 @@
+#include <iostream>
+#include <string>
+#include <vector> 
+#include <algorithm> 
+
+std::string read (char* name) {
+	FILE *f = fopen(name, "r");
+	char c = fgetc(f); std::string txt;
+	while (c != EOF) { txt += c; c = fgetc(f); }
+	fclose(f);
+	return txt;
+}
+
+std::vector<std::string> split (std::vector<std::string> vec, std::string name) {
+	auto token = name.find("\n");
+	if (token != std::string::npos) {
+		vec.push_back(name.substr(0, token));
+		return split(vec, name.substr(token+1));
+	} else if (name.size() > 1) { 
+		vec.push_back(name);
+	}
+	return vec;
+}
+
+int main (int argc, char* argv[]) {
+	if (argc < 2 && argc > 3) return 1;
+	std::string txt = read(argv[1]);
+
+	std::vector<std::string> vec;
+	vec = split(vec, txt);
+	std::vector<int> depths;
+	for (auto v : vec) {
+		depths.push_back(std::stoi(v));
+	}
+
+	int window = 1;
+	if (argc == 3) { window = atoi(argv[2]); }
+
+	int inc = 0;
+	for (std::size_t i=0; i<depths.size(); i++) {
+		if (i >= window) {
+			int sum0 = 0, sum1 = 0;
+			for (int j=0; j<window; j++) sum0 += depths[i-j-1];
+			for (int j=0; j<window; j++) sum1 += depths[i-j];
+			if (sum1 > sum0) inc ++;
+		}
+	}
+
+	std::cout << "The number of depth increases is " << inc << std::endl;
+
+	return 0;
+}
diff --git a/2021/day01/day01_input.txt b/2021/day01/day01_input.txt
new file mode 100644
index 0000000..b3ee114
--- /dev/null
+++ b/2021/day01/day01_input.txt
@@ -0,0 +1,2000 @@
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diff --git a/2021/day01/day01_input_ez.txt b/2021/day01/day01_input_ez.txt
new file mode 100644
index 0000000..167e291
--- /dev/null
+++ b/2021/day01/day01_input_ez.txt
@@ -0,0 +1,10 @@
+199
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diff --git a/2021/day01/makefile b/2021/day01/makefile
new file mode 100644
index 0000000..92fb064
--- /dev/null
+++ b/2021/day01/makefile
@@ -0,0 +1,2 @@
+all day01.cpp:
+	g++ -std=c++20 -o day01 day01.cpp
diff --git a/2021/day02/day02 b/2021/day02/day02
new file mode 100755
index 0000000..8755c57
--- /dev/null
+++ b/2021/day02/day02
diff --git a/2021/day02/day02.cpp b/2021/day02/day02.cpp
new file mode 100644
index 0000000..dccb44a
--- /dev/null
+++ b/2021/day02/day02.cpp
@@ -0,0 +1,50 @@
+#include <iostream>
+
+int main (int argc, char *argv[]) {
+	if (argc != 2) return 1;
+	
+	int depth = 0;
+   	int	forward = 0;
+
+	int aim = 0;
+	int aim_depth = 0;
+
+	FILE *f = fopen(argv[1], "r");
+	char c = fgetc(f); 
+	std::string command;
+	while (c != EOF) {
+		if (c == '\n') {
+			auto token_space = command.find(" ");
+			if (token_space != std::string::npos) {
+				std::string op = command.substr(0, token_space);
+				int amt = std::stoi(command.substr(token_space+1));
+				if (op == "forward") {
+					forward += amt;
+					aim_depth += aim * amt;
+				}
+				if (op == "down") {
+					depth += amt;
+					aim += amt;
+				}
+				if (op == "up") {
+					depth -= amt;
+					aim -= amt;
+				}
+			} 
+			command = "";
+		}
+		else command += c;
+		c = fgetc(f);
+	}
+
+	std::cout << "depth " << depth << ", "
+		<< "forward " << forward << ", "
+		<< "product " << depth * forward << std::endl;
+
+	std::cout << "using aim: depth " << aim_depth << ", "
+		<< "forward " << forward << ", "
+		<< "aim " << aim << ", "
+		<< "product " << aim_depth * forward << std::endl;
+
+	return 0;
+}
diff --git a/2021/day02/day02_input.txt b/2021/day02/day02_input.txt
new file mode 100644
index 0000000..7834464
--- /dev/null
+++ b/2021/day02/day02_input.txt
@@ -0,0 +1,1000 @@
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diff --git a/2021/day02/makefile b/2021/day02/makefile
new file mode 100644
index 0000000..61ca2f4
--- /dev/null
+++ b/2021/day02/makefile
@@ -0,0 +1,2 @@
+all day02.cpp:
+	g++ -std=c++20 -o day02 day02.cpp
diff --git a/2021/day03/day03 b/2021/day03/day03
new file mode 100755
index 0000000..ccb1732
--- /dev/null
+++ b/2021/day03/day03
diff --git a/2021/day03/day03.cpp b/2021/day03/day03.cpp
new file mode 100644
index 0000000..036cd07
--- /dev/null
+++ b/2021/day03/day03.cpp
@@ -0,0 +1,96 @@
+#include <iostream>
+#include <fstream>
+#include <string>
+#include <vector>
+
+int bin_to_dec (std::string bin) {
+	int dec = 0, pow = 1;
+	for (std::size_t i=bin.size(); i > 0; i--) {
+		dec += pow * (bin[i-1] == '0' ? 0 : 1);
+		pow *= 2;
+	}
+	return dec;
+}
+
+std::vector<int> get_freq (std::vector<std::string> bits) { 
+	std::vector<int> freq;
+	for (std::size_t i=0; i<bits[0].size(); i++) {
+		freq.push_back(0);
+	}
+
+	for (auto b : bits) {
+		for (std::size_t i=0; i< b.size(); i++) {
+		 	freq[i] += (b[i] == '0' ? 0 : 1)*2-1;
+		}
+	}
+	return freq;
+}
+
+std::vector<std::string> filter (std::vector<std::string> bits, int inv, int sel) {
+	std::vector<std::string> res;
+	auto freq = get_freq(bits);
+
+	for (auto b : bits) {
+		int f = freq[sel] * inv;
+		if (f == 0) f += inv;
+		if ((f > 0 ? '0' : '1') == b[sel]) {
+			res.push_back(b);
+		}
+	}
+
+	return res;
+}
+
+int main (int argc, char *argv[]) {
+	if (argc != 2) return 1;
+
+	std::string raw;
+	std::getline(std::ifstream(argv[1]), raw, '\0');
+
+	std::vector<std::string> bits;	
+
+	while (1) {
+		auto token = raw.find("\n");
+		if (token != std::string::npos) {
+			bits.push_back(raw.substr(0, token));
+			raw = raw.substr(token+1);
+		} else {
+			if (raw.size() > 0) bits.push_back(raw);
+			break;
+		}
+	}
+
+	auto freq = get_freq(bits);
+
+	std::string gamma = "", epsilon = "";
+	for (std::size_t i=0; i<freq.size(); i++) {
+		gamma += freq[i] > 0 ? "1" : "0";
+		epsilon += freq[i] > 0 ? "0" : "1";
+	}
+
+	int g = bin_to_dec(gamma);
+	int e = bin_to_dec(epsilon);
+	std::cout << "power level " << e*g << ", "
+   		<< "epsilon " << e << " (" << epsilon << "), "
+		<< "gamma " << g << " (" << gamma << ")" << std::endl;
+
+	std::vector<std::string> o2 = bits;
+	for (std::size_t i=0; i<freq.size(); i++) {
+		o2 = filter(o2, 1, i);
+		if (o2.size() == 1) break;
+	}
+
+	std::vector<std::string> co2 = bits;
+	for (std::size_t i=0; i<freq.size(); i++) {
+		co2 = filter(co2, -1, i);
+		if (co2.size() == 1) break;
+	}
+
+	int generator = bin_to_dec(o2[0]);
+	int scrubber = bin_to_dec(co2[0]);
+	std::cout << "oxigen generator rating " << scrubber*generator << ", "
+   		<< "epsilon " << generator << " (" << o2[0] << "), "
+		<< "gamma " << scrubber << " (" << co2[0] << ")" << std::endl;
+
+	return 0;
+}
diff --git a/2021/day03/day03_input.txt b/2021/day03/day03_input.txt
new file mode 100644
index 0000000..ac22a69
--- /dev/null
+++ b/2021/day03/day03_input.txt
@@ -0,0 +1,1000 @@
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diff --git a/2021/day03/day03_input_ez.txt b/2021/day03/day03_input_ez.txt
new file mode 100644
index 0000000..a6366a8
--- /dev/null
+++ b/2021/day03/day03_input_ez.txt
@@ -0,0 +1,12 @@
+00100
+11110
+10110
+10111
+10101
+01111
+00111
+11100
+10000
+11001
+00010
+01010
diff --git a/2021/day03/makefile b/2021/day03/makefile
new file mode 100644
index 0000000..7c21cf0
--- /dev/null
+++ b/2021/day03/makefile
@@ -0,0 +1,2 @@
+all day03.cpp:
+	g++ -std=c++20 -o day03 day03.cpp
diff --git a/2021/day04/day04 b/2021/day04/day04
new file mode 100755
index 0000000..b28d295
--- /dev/null
+++ b/2021/day04/day04
diff --git a/2021/day04/day04.cpp b/2021/day04/day04.cpp
new file mode 100644
index 0000000..7736eff
--- /dev/null
+++ b/2021/day04/day04.cpp
@@ -0,0 +1,134 @@
+#include <iostream>
+#include <fstream>
+#include <vector>
+
+void split (std::vector<std::string> &vec, std::string str, std::string del) {
+	auto token = str.find(del);
+	if (token != std::string::npos) {
+		vec.push_back(str.substr(0, token));
+		split(vec, str.substr(token+del.size()), del);
+	} else { vec.push_back(str); }
+}
+
+class Board {
+	public:
+	Board(std::string repr) { 
+		std::vector<std::string> lines;
+		split(lines, repr, "\n");
+		for (auto line : lines) {
+			std::vector<std::string> strcells;
+			split(strcells, line, " ");
+			size = 0;
+			for (auto strcell : strcells) {
+				if (strcell.size() == 0) continue;
+				cells.push_back(std::stoi(strcell));
+				state.push_back(0);
+				size++;
+			}
+		}
+
+	}
+
+	int size;
+	std::vector<int> cells;
+	std::vector<int> state;
+
+	void mark (int ex) {
+		for (int y=0; y<size; y++) {
+			for (int x=0; x<size; x++) {
+				int i = x + y*size;
+				if (cells[i] == ex) {
+					state[i] = 1;
+				}
+			}
+		}
+	}
+
+	bool win () {
+		for (int y=0; y<size; y++) {
+			int sum_row = 0;
+			for (int x=0; x<size; x++) {
+				int i = x + y*size;
+				sum_row += state[i];
+			}
+			if (sum_row == size) return true;
+		}
+		for (int x=0; x<size; x++) {
+			int sum_col = 0;
+			for (int y=0; y<size; y++) {
+				int i = x + y*size;
+				sum_col += state[i];
+			}
+			if (sum_col == size) return true;
+		}
+		return false;
+	}
+
+	int score () {
+		int sum = 0;
+		for (int y=0; y<size; y++) {
+			for (int x=0; x<size; x++) {
+				int i = x + y*size;
+				if (state[i] == 0) {
+					sum += cells[i];
+				}
+			}
+		}
+		return sum;
+	}
+};
+
+int main (int argc, char *argv[]) {
+	if (argc != 2) return 1;
+	std::string raw;
+	std::getline(std::ifstream(argv[1]), raw, '\0');
+
+	std::vector<int> extract;
+	auto token = raw.find("\n");
+	if (token != std::string::npos) {
+		std::string ex = raw.substr(0, token);
+		std::vector<std::string> vec;
+	   	split(vec, ex, ",");
+		for (auto v : vec) { extract.push_back(std::stoi(v)); }
+
+		raw = raw.substr(token+2);
+		if (raw[raw.size()-1] == '\n') raw = raw.substr(0, raw.size()-1); 
+	} else return 1;
+
+	std::vector<Board> boards;
+
+	std::vector<std::string> str_boards;
+	split(str_boards, raw, "\n\n");
+	for (auto s : str_boards) {
+		boards.emplace_back(s);
+	}
+
+	bool flag = false;
+	std::vector<Board> filtered = boards;
+	for (int ex : extract) {
+		std::cout << ex << " " << filtered.size() << std::endl;
+		std::vector<Board> next;
+		int size = filtered.size(), seen = 0;;
+		for (auto& board : filtered) {
+			board.mark(ex);
+			if (board.win() && filtered.size() != 1) {
+				if (!flag) {
+					std::cout << "first winner product: " << ex * board.score() << ", "
+						<< "ex: " << ex << ", score: " << board.score() << std::endl;
+					flag = true;
+				}
+			} else {
+				next.push_back(board);
+			}
+		}
+		if (next.size() == 1 && next[0].win()) {
+			int score = next[0].score();
+			std::cout << "last winner product: " << ex * score << ", "
+				<< "ex: " << ex << ", score: " << score << std::endl;
+			break;
+		}
+		filtered = next;
+	}
+
+	return 0;
+}
diff --git a/2021/day04/day04_input.txt b/2021/day04/day04_input.txt
new file mode 100644
index 0000000..033baa2
--- /dev/null
+++ b/2021/day04/day04_input.txt
@@ -0,0 +1,601 @@
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diff --git a/2021/day04/day04_input_ez.txt b/2021/day04/day04_input_ez.txt
new file mode 100644
index 0000000..669a51d
--- /dev/null
+++ b/2021/day04/day04_input_ez.txt
@@ -0,0 +1,19 @@
+7,4,9,5,11,17,23,2,0,14,21,24,10,16,13,6,15,25,12,22,18,20,8,19,3,26,1
+
+22 13 17 11  0
+ 8  2 23  4 24
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+ 6 10  3 18  5
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+
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+
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+ 2  0 12  3  7
diff --git a/2021/day04/makefile b/2021/day04/makefile
new file mode 100644
index 0000000..ef809af
--- /dev/null
+++ b/2021/day04/makefile
@@ -0,0 +1,2 @@
+all day04.cpp:
+	g++ -std=c++20 -o day04 day04.cpp
diff --git a/2021/day05/day05 b/2021/day05/day05
new file mode 100755
index 0000000..78ac4fc
--- /dev/null
+++ b/2021/day05/day05
diff --git a/2021/day05/day05.cpp b/2021/day05/day05.cpp
new file mode 100644
index 0000000..895dba0
--- /dev/null
+++ b/2021/day05/day05.cpp
@@ -0,0 +1,100 @@
+#include <iostream>
+#include <fstream>
+#include <string>
+#include <vector>
+#include <map>
+
+#include "../utils.h"
+
+class Line {
+	public:
+	Line (int a, int b, int c, int d) : a(a), b(b), c(c), d(d) { }
+	Line (std::string line) {
+		std::vector<std::string> parts, start, end;
+		split(parts, line, "->");
+		split(start, parts[0], ",");
+		split(end, parts[1], ",");
+		a = std::stoi(start[0]);
+		b = std::stoi(start[1]);
+		c = std::stoi(end[0]);
+		d = std::stoi(end[1]);
+		if (c-a == 0) xdir = 0;
+		else { xdir = (c-a) > 0 ? 1 : -1; }
+		if (d-b == 0) ydir = 0;
+		else { ydir = (d-b) > 0 ? 1 : -1; }
+	}
+	int a, b, c, d, xdir, ydir;
+
+	int length () { return abs(a-c) + abs(b-d); }
+
+	bool operator==(Line& oth) {
+		return a == oth.a && b == oth.b && c == oth.c && d == oth.d;
+	}
+};
+
+int main (int argc, char *argv[]) {
+	std::string raw;
+	std::getline(std::ifstream(argv[1]), raw, '\0');
+
+	std::vector<Line> lines;
+	std::vector<std::string> strlines;
+	split(strlines, raw, "\n");
+	for (auto strline : strlines) {
+		if (strline.size() == 0) continue;
+		Line line { strline };
+		if (line.xdir != 0 && line.ydir != 0 
+				&& std::stoi(argv[2]) == 0) continue;
+		lines.push_back(line);
+	}
+
+	int intersections = 0;
+	std::map<std::pair<int, int>, int> overlaps;
+	for (auto& line : lines) {
+		int dist = 0;
+		bool straight = true;
+		if (line.xdir != 0 && line.ydir != 0) straight = false;
+		for (int i=0; dist<line.length()+1; i++) {
+			std::pair pair { line.a + line.xdir*i, line.b + line.ydir*i };
+			if (overlaps.count(pair) == 0) overlaps[pair] = 1;
+			else {
+				if (overlaps[pair] == 1) intersections += 1;
+				overlaps[pair] += 1;
+			}
+			if (straight) dist ++;
+			else dist += 2;
+		}
+	}
+
+
+	int minx = 200;
+	int maxx = -200;
+	int miny = 200;
+	int maxy = -200;
+	for (auto& line : lines) {
+		minx = std::min(minx, std::min(line.a, line.c));
+		maxx = std::max(maxx, std::max(line.a, line.c));
+		miny = std::min(miny, std::min(line.b, line.d));
+		maxy = std::max(maxy, std::max(line.b, line.d));
+	}
+
+	std::cout << "bounds: " 
+		<< minx << " " << maxx << " "
+		<< miny << " " << maxx << std::endl;
+
+	/* visualizer
+	for (int y=miny; y<maxy+1; y++) {
+		for (int x=minx; x<maxx+1; x++) {
+			int amt = overlaps[std::make_pair(x, y)];
+			if (amt > 9) amt = 9;
+			if (amt > 0) std::cout << amt;
+			else std::cout << ".";
+
+		}
+		std::cout << std::endl;
+	}
+	*/
+
+	std::cout << "intersections: " << intersections << std::endl;
+
+	return 0;
+}
diff --git a/2021/day05/day05_input.txt b/2021/day05/day05_input.txt
new file mode 100644
index 0000000..58fb409
--- /dev/null
+++ b/2021/day05/day05_input.txt
@@ -0,0 +1,500 @@
+682,519 -> 682,729
+852,131 -> 25,958
+303,481 -> 206,481
+199,682 -> 183,666
+363,190 -> 571,190
+930,290 -> 221,290
+364,627 -> 952,39
+234,309 -> 234,821
+130,864 -> 130,886
+462,347 -> 699,110
+375,969 -> 481,969
+989,859 -> 275,145
+221,748 -> 212,748
+870,173 -> 106,937
+604,33 -> 604,142
+780,35 -> 780,206
+636,808 -> 721,808
+944,989 -> 334,989
+477,113 -> 192,113
+879,265 -> 879,358
+754,974 -> 17,974
+10,989 -> 989,10
+337,320 -> 674,657
+225,96 -> 557,428
+129,354 -> 299,354
+717,695 -> 695,695
+94,255 -> 317,478
+90,87 -> 90,187
+77,942 -> 952,67
+804,315 -> 989,315
+619,470 -> 491,342
+466,90 -> 466,755
+840,121 -> 840,469
+638,127 -> 638,77
+844,40 -> 151,40
+653,987 -> 653,631
+195,583 -> 195,623
+88,985 -> 570,503
+921,897 -> 165,141
+230,27 -> 171,27
+737,771 -> 832,771
+563,365 -> 665,467
+942,940 -> 776,774
+12,903 -> 644,903
+308,390 -> 308,971
+572,943 -> 572,15
+104,389 -> 104,73
+346,721 -> 974,93
+30,53 -> 562,53
+804,682 -> 804,120
+952,45 -> 15,982
+475,456 -> 475,348
+409,247 -> 664,247
+345,18 -> 816,489
+571,158 -> 505,158
+59,195 -> 27,195
+230,681 -> 23,681
+258,711 -> 921,711
+658,112 -> 366,404
+842,220 -> 842,825
+815,744 -> 540,744
+192,314 -> 703,825
+869,573 -> 869,888
+603,268 -> 603,301
+816,668 -> 816,189
+148,606 -> 948,606
+117,461 -> 506,461
+986,955 -> 986,315
+131,250 -> 192,189
+988,148 -> 518,618
+682,900 -> 31,900
+652,839 -> 652,236
+466,812 -> 466,611
+881,346 -> 401,346
+229,639 -> 731,639
+104,476 -> 840,476
+10,988 -> 988,10
+29,15 -> 987,973
+825,348 -> 825,240
+989,989 -> 10,10
+430,796 -> 926,796
+49,293 -> 610,854
+325,288 -> 918,288
+625,309 -> 439,495
+536,150 -> 356,150
+834,558 -> 822,558
+315,408 -> 315,635
+257,973 -> 813,973
+713,52 -> 122,52
+323,970 -> 578,970
+447,49 -> 829,49
+941,709 -> 941,390
+148,323 -> 391,80
+23,171 -> 23,49
+475,265 -> 322,112
+506,407 -> 69,844
+567,284 -> 483,368
+114,745 -> 114,765
+392,252 -> 109,535
+65,188 -> 455,188
+732,779 -> 732,52
+233,214 -> 759,214
+232,969 -> 957,244
+20,669 -> 20,308
+49,972 -> 285,972
+501,383 -> 433,383
+918,15 -> 32,901
+255,268 -> 935,948
+757,588 -> 757,919
+530,803 -> 284,557
+688,926 -> 48,286
+331,245 -> 331,777
+448,544 -> 209,544
+10,970 -> 951,29
+233,11 -> 897,11
+145,392 -> 628,392
+935,971 -> 935,280
+169,632 -> 54,632
+155,244 -> 155,334
+56,284 -> 205,284
+553,428 -> 553,520
+977,176 -> 497,656
+323,339 -> 971,987
+616,355 -> 616,248
+72,660 -> 72,334
+644,822 -> 510,956
+356,841 -> 587,841
+413,468 -> 605,468
+85,22 -> 645,582
+924,850 -> 522,850
+448,45 -> 345,148
+102,566 -> 551,566
+80,39 -> 847,806
+936,436 -> 934,436
+53,24 -> 495,466
+234,173 -> 282,173
+145,680 -> 456,680
+960,759 -> 960,282
+984,814 -> 308,138
+398,808 -> 716,808
+509,536 -> 25,52
+289,777 -> 803,263
+766,892 -> 257,892
+301,733 -> 688,733
+24,109 -> 887,972
+180,32 -> 577,429
+985,801 -> 687,503
+901,582 -> 586,582
+50,56 -> 50,267
+344,373 -> 437,373
+542,133 -> 905,496
+420,624 -> 420,716
+645,106 -> 645,574
+356,37 -> 114,37
+324,919 -> 357,919
+126,797 -> 120,797
+288,689 -> 435,836
+93,915 -> 639,369
+106,391 -> 478,19
+277,501 -> 714,64
+253,277 -> 643,277
+568,972 -> 350,972
+213,235 -> 213,406
+595,888 -> 595,233
+577,63 -> 37,603
+649,732 -> 931,732
+469,892 -> 549,892
+953,895 -> 953,457
+222,213 -> 290,213
+841,800 -> 841,336
+685,143 -> 25,143
+441,127 -> 441,146
+646,586 -> 56,586
+698,122 -> 465,122
+641,502 -> 641,240
+111,91 -> 185,91
+927,755 -> 874,808
+108,151 -> 108,567
+309,453 -> 309,210
+890,657 -> 491,657
+404,244 -> 404,123
+939,28 -> 26,941
+596,970 -> 596,870
+489,556 -> 489,589
+607,621 -> 903,325
+912,284 -> 571,284
+921,702 -> 743,524
+719,36 -> 719,394
+100,905 -> 798,207
+316,260 -> 316,887
+799,940 -> 885,940
+835,287 -> 199,923
+422,760 -> 64,760
+727,113 -> 727,679
+733,56 -> 59,730
+141,399 -> 485,743
+769,629 -> 769,797
+62,486 -> 62,205
+192,332 -> 800,332
+15,931 -> 727,931
+854,915 -> 988,915
+349,610 -> 886,610
+72,110 -> 72,903
+955,110 -> 78,987
+591,553 -> 591,428
+708,467 -> 516,467
+397,589 -> 353,589
+930,336 -> 930,532
+639,50 -> 228,50
+472,17 -> 472,244
+420,825 -> 420,562
+203,197 -> 203,35
+984,964 -> 223,203
+944,269 -> 935,260
+933,119 -> 87,965
+696,290 -> 696,580
+925,960 -> 52,87
+451,470 -> 235,254
+562,71 -> 562,149
+405,126 -> 405,67
+356,424 -> 356,673
+859,649 -> 859,291
+210,651 -> 210,544
+403,783 -> 403,122
+672,87 -> 586,87
+409,668 -> 984,668
+917,352 -> 511,758
+395,953 -> 141,953
+152,795 -> 152,313
+839,344 -> 811,372
+114,649 -> 650,649
+60,517 -> 60,27
+448,392 -> 845,392
+33,849 -> 719,163
+151,988 -> 876,988
+805,556 -> 124,556
+361,538 -> 706,193
+974,941 -> 141,108
+271,813 -> 968,116
+500,697 -> 80,277
+586,731 -> 586,480
+128,147 -> 174,101
+882,681 -> 882,745
+531,730 -> 677,730
+989,11 -> 11,989
+74,332 -> 234,492
+360,326 -> 932,898
+136,288 -> 113,311
+666,645 -> 916,895
+977,478 -> 561,62
+20,83 -> 566,83
+331,942 -> 331,646
+180,291 -> 405,291
+637,763 -> 637,941
+120,138 -> 120,820
+951,24 -> 14,961
+204,304 -> 204,51
+84,168 -> 880,168
+955,145 -> 955,903
+437,427 -> 437,354
+875,67 -> 189,753
+46,767 -> 802,11
+52,59 -> 889,896
+926,56 -> 102,880
+500,30 -> 964,30
+329,488 -> 329,972
+63,11 -> 889,837
+707,168 -> 707,584
+580,10 -> 735,10
+105,620 -> 105,110
+187,531 -> 323,531
+82,947 -> 82,941
+737,199 -> 737,851
+612,650 -> 217,650
+971,15 -> 82,904
+16,590 -> 506,100
+950,877 -> 832,759
+570,470 -> 570,276
+213,411 -> 213,195
+670,755 -> 89,755
+906,963 -> 906,984
+458,463 -> 442,463
+956,969 -> 10,23
+87,215 -> 195,107
+819,454 -> 819,467
+594,793 -> 686,793
+395,724 -> 787,332
+315,461 -> 644,461
+448,247 -> 249,48
+620,302 -> 247,675
+607,134 -> 932,134
+312,776 -> 312,289
+850,942 -> 54,146
+31,538 -> 851,538
+729,126 -> 640,126
+702,199 -> 702,706
+402,783 -> 254,783
+110,59 -> 203,59
+27,10 -> 965,948
+747,261 -> 47,261
+628,742 -> 972,742
+712,742 -> 657,797
+877,871 -> 877,758
+665,313 -> 449,529
+498,157 -> 498,68
+870,922 -> 27,79
+856,697 -> 856,429
+447,271 -> 963,787
+495,302 -> 495,520
+526,47 -> 721,47
+826,179 -> 826,741
+565,461 -> 893,461
+512,328 -> 127,328
+487,920 -> 522,920
+614,452 -> 614,146
+331,574 -> 331,840
+985,79 -> 285,779
+812,320 -> 985,320
+118,69 -> 429,69
+644,525 -> 644,878
+271,132 -> 156,132
+955,782 -> 565,392
+630,939 -> 630,372
+51,203 -> 840,203
+202,490 -> 202,479
+579,868 -> 579,92
+979,336 -> 979,623
+843,865 -> 260,282
+685,872 -> 685,503
+721,193 -> 721,510
+908,661 -> 908,955
+19,950 -> 715,254
+233,730 -> 233,101
+922,954 -> 27,954
+399,444 -> 399,403
+380,712 -> 380,718
+238,264 -> 849,875
+458,577 -> 458,139
+418,244 -> 469,295
+460,375 -> 964,879
+276,445 -> 815,445
+463,910 -> 648,725
+26,384 -> 968,384
+955,385 -> 955,143
+942,775 -> 733,566
+425,326 -> 531,326
+364,545 -> 364,873
+182,759 -> 182,819
+390,757 -> 390,475
+217,417 -> 217,157
+669,286 -> 65,890
+257,11 -> 257,858
+557,397 -> 557,20
+888,946 -> 32,90
+971,938 -> 971,578
+874,248 -> 874,485
+87,268 -> 87,135
+756,679 -> 103,26
+771,250 -> 771,107
+320,711 -> 967,711
+293,219 -> 293,706
+103,565 -> 103,538
+388,256 -> 388,261
+468,953 -> 503,953
+424,142 -> 287,142
+24,930 -> 850,930
+316,167 -> 316,161
+481,421 -> 208,148
+938,926 -> 938,933
+701,653 -> 701,780
+536,390 -> 536,559
+40,954 -> 829,165
+404,985 -> 247,985
+94,628 -> 94,500
+441,637 -> 441,271
+766,946 -> 97,277
+428,363 -> 428,37
+542,694 -> 542,347
+11,16 -> 979,984
+938,651 -> 632,957
+779,127 -> 243,663
+636,294 -> 636,787
+533,744 -> 636,641
+521,950 -> 458,950
+988,12 -> 18,982
+954,621 -> 954,271
+638,951 -> 813,951
+822,911 -> 632,911
+714,849 -> 512,849
+696,88 -> 385,88
+65,451 -> 65,687
+976,973 -> 976,907
+368,489 -> 368,571
+358,831 -> 690,499
+436,704 -> 178,704
+690,619 -> 606,535
+96,701 -> 358,701
+885,562 -> 420,562
+581,480 -> 613,512
+44,970 -> 970,44
+216,796 -> 892,120
+72,623 -> 72,72
+896,283 -> 896,326
+794,195 -> 22,967
+134,326 -> 134,889
+420,141 -> 944,665
+941,194 -> 941,421
+940,525 -> 298,525
+653,300 -> 769,300
+227,424 -> 406,603
+275,850 -> 113,850
+648,850 -> 92,850
+638,389 -> 638,10
+379,404 -> 584,609
+833,931 -> 833,520
+772,286 -> 500,558
+372,262 -> 333,262
+689,18 -> 131,576
+687,499 -> 687,188
+344,499 -> 37,806
+778,496 -> 134,496
+938,87 -> 344,681
+788,401 -> 479,401
+828,903 -> 756,903
+423,625 -> 285,763
+218,489 -> 218,819
+488,384 -> 891,787
+817,532 -> 788,532
+512,27 -> 512,149
+369,794 -> 54,794
+534,590 -> 827,883
+84,310 -> 39,265
+357,545 -> 665,545
+539,807 -> 539,781
+378,683 -> 22,327
+71,909 -> 943,37
+740,552 -> 348,552
+698,315 -> 45,968
+516,835 -> 360,835
+629,141 -> 629,385
+695,908 -> 303,908
+795,707 -> 386,707
+211,397 -> 291,397
+64,620 -> 236,620
+97,638 -> 97,445
+46,103 -> 893,950
+468,122 -> 979,122
+810,486 -> 433,486
+532,899 -> 461,970
+232,60 -> 235,60
+549,708 -> 549,90
+294,978 -> 294,124
+865,406 -> 640,406
+755,305 -> 664,305
+12,989 -> 987,14
+275,249 -> 260,234
+502,783 -> 67,783
+863,938 -> 297,372
+516,961 -> 516,272
+67,510 -> 611,510
+980,951 -> 312,283
+325,512 -> 325,169
+142,429 -> 542,29
+273,964 -> 822,964
+370,217 -> 508,217
+131,131 -> 331,331
+734,824 -> 734,817
+75,89 -> 687,701
+155,255 -> 702,802
+577,395 -> 130,395
+684,94 -> 555,94
+393,881 -> 173,881
+894,750 -> 773,750
+380,269 -> 380,338
+427,36 -> 427,77
+637,107 -> 637,846
+53,437 -> 53,221
+128,979 -> 960,147
+838,211 -> 838,645
+898,39 -> 849,39
+862,495 -> 951,495
+754,406 -> 76,406
+951,960 -> 113,122
+830,125 -> 15,940
+190,117 -> 190,973
+192,956 -> 718,430
+895,162 -> 88,969
+135,196 -> 70,131
+578,642 -> 578,789
+713,268 -> 625,268
+938,719 -> 938,604
+30,863 -> 99,863
+844,309 -> 287,309
+131,837 -> 459,509
+61,206 -> 722,867
+95,974 -> 283,974
+746,672 -> 558,672
+552,32 -> 352,32
+21,637 -> 21,781
+945,847 -> 945,303
diff --git a/2021/day05/day05_input_ez.txt b/2021/day05/day05_input_ez.txt
new file mode 100644
index 0000000..b258f68
--- /dev/null
+++ b/2021/day05/day05_input_ez.txt
@@ -0,0 +1,10 @@
+0,9 -> 5,9
+8,0 -> 0,8
+9,4 -> 3,4
+2,2 -> 2,1
+7,0 -> 7,4
+6,4 -> 2,0
+0,9 -> 2,9
+3,4 -> 1,4
+0,0 -> 8,8
+5,5 -> 8,2
diff --git a/2021/day05/makefile b/2021/day05/makefile
new file mode 100644
index 0000000..a197e7d
--- /dev/null
+++ b/2021/day05/makefile
@@ -0,0 +1,2 @@
+all day05.cpp:
+	g++ -std=c++20 -o day05 day05.cpp
diff --git a/2021/day06/day06 b/2021/day06/day06
new file mode 100755
index 0000000..ccf553a
--- /dev/null
+++ b/2021/day06/day06
diff --git a/2021/day06/day06.cpp b/2021/day06/day06.cpp
new file mode 100644
index 0000000..38d602b
--- /dev/null
+++ b/2021/day06/day06.cpp
@@ -0,0 +1,47 @@
+#include <iostream>
+#include <fstream>
+#include <string>
+#include <vector>
+
+#include "../utils.h"
+
+long sum (std::vector<long> vec) {
+	long s = 0; for (long v : vec) s += v; return s;
+}
+
+int main (int argc, char *argv[]) {
+	std::string raw;
+	std::getline(std::ifstream(argv[1]), raw, '\0');
+	std::vector<std::string> strfish;
+	split(strfish, raw, ",");
+	
+	std::vector<long> fish;
+	for (int i=0; i<9; i++) { fish.push_back(0); }
+	for (std::string str : strfish) fish[std::stoi(str)] += 1;
+
+	int days = 80;
+	if (argc > 2) days = std::stoi(std::string(argv[2]));
+	for (int i=0; i<days; i++) {
+		long born = fish[0];
+		fish[0] = 0;
+		for (int j=1; j<9; j++) {
+			fish[j-1] += fish[j];
+			fish[j] = 0;
+		}
+		fish[6] += born;
+		fish[8] = born;
+	
+		if (argc > 3 && std::string(argv[3]) == "-w") {	
+			std::cout << "day " << i+1 << "/" << days 
+				<< " current fish: " << sum(fish) << std::endl;
+		}
+		if (argc > 3 && std::string(argv[3]) == "-v") {	
+			std::cout << "day " << i+1 << ": ";
+			for (auto f : fish) std::cout << f << ",";
+			std::cout << std::endl;
+		}
+	}
+
+	std::cout << "fish: " << sum(fish) << std::endl;
+	return 0;
+}
diff --git a/2021/day06/day06_input.txt b/2021/day06/day06_input.txt
new file mode 100644
index 0000000..5b38bce
--- /dev/null
+++ b/2021/day06/day06_input.txt
@@ -0,0 +1 @@
+4,1,1,4,1,1,1,1,1,1,1,1,3,4,1,1,1,3,1,3,1,1,1,1,1,1,1,1,1,3,1,3,1,1,1,5,1,2,1,1,5,3,4,2,1,1,4,1,1,5,1,1,5,5,1,1,5,2,1,4,1,2,1,4,5,4,1,1,1,1,3,1,1,1,4,3,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,5,1,1,2,1,1,1,1,1,1,1,2,4,4,1,1,3,1,3,2,4,3,1,1,1,1,1,2,1,1,1,1,2,5,1,1,1,1,2,1,1,1,1,1,1,1,2,1,1,4,1,5,1,3,1,1,1,1,1,5,1,1,1,3,1,2,1,2,1,3,4,5,1,1,1,1,1,1,5,1,1,1,1,1,1,1,1,3,1,1,3,1,1,4,1,1,1,1,1,2,1,1,1,1,3,2,1,1,1,4,2,1,1,1,4,1,1,2,3,1,4,1,5,1,1,1,2,1,5,3,3,3,1,5,3,1,1,1,1,1,1,1,1,4,5,3,1,1,5,1,1,1,4,1,1,5,1,2,3,4,2,1,5,2,1,2,5,1,1,1,1,4,1,2,1,1,1,2,5,1,1,5,1,1,1,3,2,4,1,3,1,1,2,1,5,1,3,4,4,2,2,1,1,1,1,5,1,5,2
diff --git a/2021/day06/day06_input_ez.txt b/2021/day06/day06_input_ez.txt
new file mode 100644
index 0000000..55129f1
--- /dev/null
+++ b/2021/day06/day06_input_ez.txt
@@ -0,0 +1 @@
+3,4,3,1,2
diff --git a/2021/day06/makefile b/2021/day06/makefile
new file mode 100644
index 0000000..2bc132f
--- /dev/null
+++ b/2021/day06/makefile
@@ -0,0 +1,2 @@
+all day06.cpp:
+	g++ -std=c++20 -o day06 day06.cpp
diff --git a/2021/day07/day07 b/2021/day07/day07
new file mode 100755
index 0000000..4cbc735
--- /dev/null
+++ b/2021/day07/day07
diff --git a/2021/day07/day07.cpp b/2021/day07/day07.cpp
new file mode 100644
index 0000000..f9bbd1a
--- /dev/null
+++ b/2021/day07/day07.cpp
@@ -0,0 +1,40 @@
+#include <iostream>
+#include <fstream>
+#include <string>
+#include <vector>
+
+#include "../utils.h"
+
+long sumdist (std::vector<int> pos, int pole, int inc) {
+	long sd = 0;
+	for (auto p : pos) { 
+		int n = abs(p-pole); 
+		if (inc == 1) n = (n * (n+1)) / 2;
+		sd += n;
+   	}
+	return sd;
+}
+
+int main (int argc, char *argv[]) {
+	std::string raw;
+	std::getline(std::ifstream(argv[1]), raw, '\0');
+	std::vector<std::string> vec;
+	split(vec, raw, ",");
+	std::vector<int> pos;
+	for (auto s : vec) pos.push_back(std::stoi(s));
+	
+	int minp = 10000, maxp = -10000;
+	for (auto p : pos) {
+		minp = std::min(minp, p);
+		maxp = std::max(maxp, p);
+	}
+	int inc = argc > 2 ? atoi(argv[2]) : 0;
+	long fuel = 100000000000;
+	for (int i=minp; i<maxp; i++) {
+		fuel = std::min(fuel, sumdist(pos, i, inc));
+	}
+	
+	std::cout << "fuel: " << fuel << std::endl;
+
+	return 0;
+}
diff --git a/2021/day07/day07_input.txt b/2021/day07/day07_input.txt
new file mode 100644
index 0000000..4ac01fd
--- /dev/null
+++ b/2021/day07/day07_input.txt
@@ -0,0 +1 @@
+1101,1,29,67,1102,0,1,65,1008,65,35,66,1005,66,28,1,67,65,20,4,0,1001,65,1,65,1106,0,8,99,35,67,101,99,105,32,110,39,101,115,116,32,112,97,115,32,117,110,101,32,105,110,116,99,111,100,101,32,112,114,111,103,114,97,109,10,601,578,981,315,530,525,671,1501,616,214,724,1247,543,58,183,282,242,54,90,130,1788,360,1719,710,1165,1476,29,744,164,293,1360,274,47,119,16,387,134,547,72,48,77,416,863,39,65,144,500,678,430,160,1689,550,753,1478,480,56,583,85,206,93,335,990,174,276,1119,52,308,470,563,387,897,21,85,720,983,178,383,134,299,722,57,391,489,768,232,646,1312,1316,31,57,927,176,531,421,1162,369,934,7,172,237,340,169,261,1371,1351,1268,72,58,375,1570,1238,55,513,403,1462,141,263,419,1316,852,251,39,358,209,204,439,150,1667,344,205,1299,1226,992,967,536,1160,1503,1154,1323,486,1079,329,823,506,1252,387,28,69,649,296,233,62,219,344,464,1284,291,234,47,949,1126,935,1367,1450,1431,379,344,478,731,648,77,184,927,211,262,728,1093,381,140,239,332,1436,78,665,1486,601,1444,364,1057,753,488,127,1001,350,1016,357,638,309,40,333,136,655,779,821,414,275,140,149,185,445,1169,476,196,907,1570,193,161,43,204,1489,1125,1024,101,17,592,1378,338,1625,3,269,1568,254,803,25,776,109,52,291,1595,255,739,34,768,378,632,4,181,373,162,562,74,85,160,16,47,38,266,1610,9,7,1398,358,287,450,188,1390,37,98,80,685,1645,50,55,16,542,20,443,848,49,808,76,233,69,110,471,73,408,638,89,861,280,1062,75,314,808,237,96,401,57,48,1306,115,1164,1533,5,1032,1314,66,630,96,496,116,1558,438,13,182,1360,802,101,327,370,444,335,812,430,900,1259,1117,318,118,433,501,401,101,582,27,454,981,776,14,26,163,384,1652,87,788,474,588,155,845,207,33,200,622,840,1360,432,11,525,86,296,481,200,529,95,924,431,40,846,220,285,14,66,755,111,647,643,1201,81,483,555,125,426,1499,29,115,48,39,92,316,434,217,218,116,9,33,496,358,1106,736,1181,1153,117,20,1719,1113,1620,26,581,407,114,1559,6,1918,964,909,340,630,817,473,111,1485,434,262,1702,651,11,182,1043,1904,633,336,252,677,1238,637,1008,82,327,171,185,19,141,395,1209,53,798,836,1378,598,262,298,265,287,85,21,249,848,162,89,1050,108,34,41,25,291,918,28,1234,139,351,867,146,79,995,1173,635,24,31,81,214,1114,155,1256,159,206,586,426,452,650,1653,47,42,264,240,500,864,893,1308,1249,853,286,62,592,102,77,1082,91,120,625,211,978,319,655,200,152,86,396,52,308,1479,38,41,53,179,648,216,41,641,659,1556,226,1421,291,33,1461,1095,529,309,1100,314,1695,505,1200,150,946,53,124,139,1506,52,33,463,613,33,1264,386,678,563,564,318,273,912,60,31,150,1321,133,1333,302,1243,49,421,808,1399,555,195,611,268,39,1302,1154,92,664,117,92,124,332,561,1436,865,198,71,271,909,40,1185,664,251,422,306,122,814,158,1676,122,217,312,952,845,104,572,1796,392,651,176,714,44,757,111,56,489,333,738,369,304,1239,105,297,277,674,213,938,2,681,336,171,1252,166,88,489,273,260,565,231,319,1085,650,211,510,12,511,325,46,107,980,1136,16,95,308,935,514,469,20,44,209,345,467,1310,500,75,594,166,199,741,193,28,52,106,1437,366,575,1200,609,678,534,573,723,325,8,386,268,690,321,186,375,2,104,657,1341,601,175,0,745,146,508,180,426,811,7,215,300,86,25,372,233,900,276,1625,808,1941,510,234,813,131,334,58,783,992,236,244,174,609,1581,1767,204,187,208,1340,347,803,146,299,140,142,339,60,118,300,809,276,413,267,946,77,154,466,425,193,187,852,674,2,17,1006,1007,166,195,137,97,41,407,65,1072,20,789,311,1227,20,132,1536,995,194,506,635,115,1500,529,93,72,950,208,944,1177,476,207,1228,5,974,226,225,290,690,581,218,401,49,361,1408,242,254,24,313,441,635,126,513,994,299,1722,52,1123,44,1332,628,534,789,298,692,45,596,1583,77,15,38,1293,1181,1498,772,148,297,49,692,87,594,49,148,170,54,1079,7,468,847,336,421,34,1108,406,892,689,245,298,85,1187,1142,286,310,207,34,660,549,39,1172,97,1,750,47,0,77,1632,135,54,18,22,1292,230,1031,11,225,820,461,1208,108,1443,274,1134,41,287,166,274,1032,585,1491,75,549,1231,1314,443,212,395,386,698,58,644,395,81,905,366,233,716,656,799,643,1011,173,790,360,269,930,13,606,488,387,1206,51
diff --git a/2021/day07/day07_input_ez.txt b/2021/day07/day07_input_ez.txt
new file mode 100644
index 0000000..18bd32a
--- /dev/null
+++ b/2021/day07/day07_input_ez.txt
@@ -0,0 +1 @@
+16,1,2,0,4,2,7,1,2,14
diff --git a/2021/day07/makefile b/2021/day07/makefile
new file mode 100644
index 0000000..2856268
--- /dev/null
+++ b/2021/day07/makefile
@@ -0,0 +1,2 @@
+all day07.cpp:
+	g++ -std=c++20 -o day07 day07.cpp
diff --git a/2021/day08/day08 b/2021/day08/day08
new file mode 100755
index 0000000..7f591be
--- /dev/null
+++ b/2021/day08/day08
diff --git a/2021/day08/day08.cpp b/2021/day08/day08.cpp
new file mode 100644
index 0000000..30b818b
--- /dev/null
+++ b/2021/day08/day08.cpp
@@ -0,0 +1,72 @@
+#include <iostream>
+#include <fstream>
+#include <vector>
+#include <string>
+
+#include "../utils.h"
+
+int distance (std::string a, std::string b) {
+	int d = 0;
+	for (auto k : b) {
+		if (a.find(k) == std::string::npos) d++;
+	} return d;
+}
+
+int map (std::vector<std::string> tries, std::string dig) {
+	if (dig.size() == 2) return 1;
+	if (dig.size() == 3) return 7;
+	if (dig.size() == 4) return 4;
+	if (dig.size() == 7) return 8;
+	if (dig.size() == 4) return 8;
+	
+	std::string one = *std::find_if(std::begin(tries), std::end(tries), 
+		[](std::string &str){ return str.size() == 2; });
+	std::string four = *std::find_if(std::begin(tries), std::end(tries), 
+		[](std::string &str){ return str.size() == 4; });
+	if (dig.size() == 5) {
+		if (distance(dig, one) == 0) return 3;
+		if (distance(dig, four) == 1) return 5;
+		return 2;
+	}
+	if (dig.size() == 6) {
+		if (distance(dig, one) == 1) return 6;
+		if (distance(dig, four) == 0) return 9;
+	}
+	return 0;
+}
+
+int main (int argc, char *argv[]) {
+	std::string raw;
+	std::getline(std::ifstream(argv[1]), raw, '\0');
+	std::vector<std::string> lines, parts;
+	split(lines, raw, "\n");
+
+	std::vector<int> count;
+	for (int i=0; i<8; i++) count.push_back(0);
+
+	int sum = 0;
+	for (auto line : lines) {
+		if (line.size() == 0) continue;
+		parts.clear();
+		split(parts, line, " | ");	
+
+		std::vector<std::string> tries, digits;
+		split(tries, parts[0], " ");
+		split(digits, parts[1], " ");
+
+		int i = 1000;
+		int num = 0;	
+		for (auto dig : digits) {
+			count[dig.size()]++;
+			num += i*map(tries, dig);
+			i/=10;
+		}
+		sum += num;
+	}
+
+	std::cout << "digits: " << count[2] + count[3] + count[4] + count[7] 
+		<< std::endl;
+	std::cout << "sum: " << sum << std::endl;
+
+	return 0;
+}
diff --git a/2021/day08/day08_input.txt b/2021/day08/day08_input.txt
new file mode 100644
index 0000000..cf25f77
--- /dev/null
+++ b/2021/day08/day08_input.txt
@@ -0,0 +1,200 @@
+bfdcga cgdfe egfda cbfeda ec efc gcfbd ebcg gdfbec adcgfeb | bgdfc ec dfgae gefcd
+cafgbd bc gfdbae eacfb cbf debaf cdgefba fecag fbcdae ecbd | cdfabg cb adgfcb bface
+afg daecgf aefbgdc fbge fg dabfg efabgd cbadge abcfd gbaed | acbdf egbda adbge fg
+cbeafg fadce cdeabfg gbdefc ged ebcgf bfgd dg ecdgf bgedac | fgdb afcbeg gcfeba edg
+efd aegdb efgdcb bafcd acef dfaeb ef fgbadec cadfgb bfecda | fedgcb begcfd def gfdbac
+badce gbcda gad fgdc acbgf cfbage gcfbad gd dbafeg afcbged | ebdfag dfcbag gd fdeagb
+gdbcaf da dcbeg cad edcbfg gdea baedc afbec baegdc gbfaedc | gbdcaf dbgec da gaed
+bedga agbefd dbgfca gcafdbe begcdf gdabf abegc deb ed adef | bgade gacbe ebd cbefdg
+eg edfcab gfde abedf fbgdea bgcad gefcba agbed ebg eafbcgd | ge fbdeca bdcfega cgadb
+dgbaecf fegbd de fbgade fde gecfb ebda dbgfa dfegca dfagbc | afcegd fgdabce de efgdac
+dgafe deafbg gdecbfa fgcad beagd gfbcae efa dbfe ef dcgeba | gafedb debacg ef dfbe
+gbadcf bcade efdgbac bcf acebf bf egcfa ebdf acbgde cdabfe | fbcea eafcg fcbea dcbafge
+dcfbge ecdabg gfbdae afecb cbg cbgae gacedbf gadc cg bedag | bgdae becga bdcgfe ebcgda
+bde eb cgbfade cdgbef beag gabdf dafeb cadfe agdfcb eadgfb | begfdc dfbcga abfdg edagbf
+dcbgea fced cgeaf cfaged gdeac dgbfca fc badgfce cfg egbfa | fbcdag feagb cdef fcg
+gfdbc adebcg cbg dfcaeb cg bcaefdg bdgfec bdagf dcfeb egcf | fbgda aedfcb cfgbde defgcb
+daf cagfeb adeg dcbef cdgbaf da efcag fbdegca ecafd dcaegf | da bgeafc bgdfac ecgdaf
+gfdaeb gfde agebf bgf fg bgcfad afbde fdaecb dbeacfg eabcg | gecab baedf eadfb gcbdfa
+bagcfed eafb acfgd cebdfg ead agbdef baedcg egfbd agefd ea | gacfd bgfed fgdae bfdeg
+cgfab adcfebg cgdef eabc feagbd ebcfg feb eb bdfcga gbcfae | defgc bdcafg fgdec cegbf
+cdfab gdf cfebg decbaf gd dcgbaf gcbfd cgad egdbaf badcfeg | gfcbd gd cbgfe ecbafd
+faebd ba efacgd baedcf adcef abf dcfbgae dbac gdbfe begcaf | dcab dafec fecadg ebdfa
+dfceab egbadcf ba fdcbg feba cgdfae dbegac abdfc cba ecfad | defacg dgbcf gbdcf efcdbga
+cadgb bedg fgaceb eacbgd egbac cefadg gd cafdb eabgdfc gad | afgdce adcgb gbacd adg
+acb adcgf adcfeb baedg cb becagd bfcadge abcdg ebgc gfdeba | gdafc acfdeb cb aebgd
+fabcgd fcdgae facde bcafeg da geda gcebadf befcd eagfc adf | cfage fgeac fgdbaec fgeac
+bafeg fabcdg efdgabc fgdbea gdae ae dgafb bae ebgcf fcadbe | begcf abgfe aegbf efbadc
+fdeca cadegbf gce bafdge abcdeg dcgb ebcfga cg deagb dagce | bdeag aebdgf gce dbage
+fcgbde cdgaebf dgbaef fed bade ed adfgb efdag fdabcg agefc | gfdab adbcfg gcfae dfagb
+ebdgfc febad adbfc fc bdfcea badfge cfb eafc acdgb egcfdba | acbgd bgfead dfabc fcea
+eb ebaf cbdgef gaedb afgebdc febdag dgefac agbcd beg deagf | dgfcea efabdg egabd geafd
+cedfba efgbd gfbdac gfaecd bfa gdfba bcag ab cgdfa begdafc | dfbace dfgeb eafcdbg dfcag
+cfdbge gdbefac dabf dgbcfa gacdf gebca fb agefdc bcgaf fbc | afbd gbcafed acgeb ebgfdc
+fgbec fbgcd fdbaceg gafedc bfacge fge eafb agbced cbgea fe | abgce fadegc ebacg fagecd
+bdgec bgecfa fcbed debfcg acebfd gcb adbecgf gb aegcd gbdf | ebgfdc geacbfd gcb gb
+fbea bdfcag dceabg egfcd edcfbga abdge af adf dfbage egfad | fa deacgb agfdbce ebdag
+abdecfg gbacf fdbcge gfd dg gdafbc adgb acfde fadgc fbeagc | dcgebf dacgf agfbc cdagbf
+agcefd ged bdfagc ed ebdgf fcdbge dgfbc abegf cdfegab debc | cagdfe ged cgdafb bafdcg
+cebgad fdgea abgf fdbcae af baedg dgfeba dfbagce edgfc fea | dabegcf agdbe afe acfedb
+agdfe fedbcga gfedbc agcbe edb db fdba edbgaf gedafc abdeg | cdgabfe afegbd fegbcd eafgd
+dea abgdfe edgfbac egdab de cadbef adfbg gbcea gfde dabgfc | cdafeb ed bafgde ed
+adgfb cdgefa ea fea bcdef cfagbd fgecabd febda agbe fgabed | cdefb gbea bdacfg dcbef
+cadbg ea fdgeab afcedg dae ebcfdga cdfge afec dbfgce ceagd | fbeacdg dgcab bgdca dae
+ecdbfg caebd fcgde fgda aefbcg afedc fcabegd aef gcdaef af | ecdfa bdecfg fea dgcfbea
+dbcagf afgec fcadb ead daefc dbcgae edfb cagbdfe fcdbae de | egdabc fdagbc cgafbd afdec
+dgfabe egdcbfa beacdg dbcfg aefc cdbaf fbadec fa aedbc fab | eacf bcdfg efca ecbad
+defbgc gbdef cg edgc egbadfc cbgef gafdeb gcf eacbf gbfdca | fbedg decg cgf egfcb
+cfdgae abdgf gbcd cfdaeb afebcgd cafgd bdf bcfgad db gefba | egfba decgfa abfeg eafdcg
+dfagb gdbface adefbc gbfae gae begc acebgf fdgeca ge cefba | cgefab dfgace fecagd beadfc
+fedacgb ed cabdfg bfgade dbaefc gdfba def gead bgcfe bdfeg | adcefb gdbaf egad caebdf
+agfbed ecfbg cdge cgb fcgbde ebcaf adfbcg dcegabf cg efdgb | bdfcga bfeadg ecgfb cg
+bec becfdag bgcaf eb debf adcef cefba fbcade acbged fcadge | edacfb fdeca fgabc cgafb
+bfcae gabc fegcdb adefgbc bcgfae gfb fbgea fdabec adgfe bg | dfcgeb fgbae fgb bedgfc
+afedcbg ed dfagc gefcd dec agbdec bfecg gfedca efad dfabcg | edaf dec begadc dfagbc
+cgebd befcadg ecg ec fcde dbfgc fgdabc becfga aegbd bfcged | cbgafd bcgfd fedc gfdbec
+dfabeg acfebd bgfcde begfd bcagd cdafgbe gabed aeb fgae ea | gbedf gdebfa bfegcd bgefd
+gdf dagec gf cfdbega cfdba edbcga ceadfg fcdag aegf cdbfge | eafg fgd dfg bdegcf
+bcfae fabge cdegabf cdae ebc dfcba ecbdfg ce dagcfb fbedca | fdagcb bcedfa fceabdg adce
+cgbaf ad fgcadeb cbfdae fbgdac bgda egdfc cefbag adc fcadg | cfdgbae adc ecafgb dgabfc
+bafdc cfb cf abcfged acdbge dbgca aefdb afcg afcdgb gbefdc | dabfc cagf efbcgd abecdgf
+de abgefdc fbed adbcgf gaecf eda aebdgf adbecg fegda bfagd | feagbd dbgfac ade adgfe
+gacefb faebcgd decfgb fa abdgfe afb fdbge dacbg adfgb edfa | dgbac abcgd gbadc adbgf
+fbadg fgbde fagebd agbcf gad gfcbed abde da cbdfaeg afegdc | ecfbdg agd efdgcba aefbdg
+cbdge gfecd cfe cafgd dbfe fe bgefdca gedfcb gebfac dgbcea | dgecb bagcfde gecbaf gacbef
+dfgecb agbfe dbeacf ebcdf cbad cadfbeg ca cfa abcef edfcga | afgdbce cabd fcbdae becaf
+abcd fbade befdcag da fecdag ecfdab bgfced bfedc dae gbaef | da ebfdc cabd cfedbg
+ecdab cfaged cbfd cfebad begda agbfce fecba cd acd fedcbga | cfdage daecb febca ebacf
+fcdageb beadf dag dacfbg bacge deabg dfcabe gdbaef degf gd | bafcdg dgafbc bdaef gd
+febcg cefbagd fegdbc bfeac ab gcba bfa fdbega cedfa cgfeab | eagbcf cbgef afb fcgbae
+egfac acbdge fadcbg bgcedfa bdcafe bf ecadb fdeb fecba bfc | fgdcabe dcbfga aegcf fbcadeg
+gcfebd acdgb faedcb gcdfb fd gdfe fcgbe fgacdeb baefcg dbf | cgfdb bgdcf gabcd edcbgf
+aced fbacg adbcf cd fbade cdb decfbg faegdcb gedabf ecdfba | bdfae fdgcbae fdbgec fdecgb
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+gbeacfd gacbd dcgfbe fg fgd dbacge bdagcf dfcea gafb fgadc | deagcb gf degfbc edcgbaf
+ce gdbcae debcf cfdabe eacfbdg acef fgdbc begadf ecd afdbe | dbefa abegdc cbdfg acfbed
+begdfc gbdc gedaf dc edgfc cdf fgbec ecdafb ebgafc degcbfa | egdfa edgbfca cbefg fagcbe
+efcab dgbfc ag agdc cfagbde fbgeda fag acgdfb fcbga gbefcd | gacd gdac dcag gdac
+bdage bdaefg gbe eb edfb bgafec dgbecaf egadf fdaecg dbacg | geb afgdbe dfbegac efgcba
+ecgfa bec be ebfgc dgbcea adefgc egafbc egbafcd bafe gbfdc | aefb bce befa gfecab
+ebgdc cbe ecdgab gacb gfced dbgea edbcfa fagcdeb gabfde bc | dgfec aebdgf abcdfeg fbaedc
+daegbf adef dgcabe cafdgbe adcgfb dbegf ebgcf dbf ebadg fd | fcbge bgcef acfgdb efbgd
+cdbge cfe adbcef fedgcb gfebcda cedgf edagf gdbcae cf gcfb | cdbeg gcdfe fabgdce aecbfd
+beacg dafge gbeadc fcba bgdeafc begfa bf eabcfg ebgcdf bfg | gaefb bcfged degcab egdaf
+acgefbd feb bf cdaef beadf gbaed abgced gabdef abfg gbfedc | begfda efcda bfe dgacbe
+eacfgd fbdgce abfcge bcfea cafeg cagdbfe ebf debca bf fgba | fb fb acdbe cfdage
+bfec cedagf aef ef degba bagcef dgcfab fgeab fecdgba bacfg | cbgaef efacgd aegfb aef
+dbacfe edfc ec caebd agfebc cbe cbdag gfcbead bgfead bafde | deabc dfagbe cgbfea ec
+ed dfgbec dfabg fbaec feacbg edafb aedc eadfcgb ebdacf dbe | deac bgeafc cebfdg fcdegb
diff --git a/2021/day08/day08_input_ez.txt b/2021/day08/day08_input_ez.txt
new file mode 100644
index 0000000..c9f629b
--- /dev/null
+++ b/2021/day08/day08_input_ez.txt
@@ -0,0 +1,10 @@
+be cfbegad cbdgef fgaecd cgeb fdcge agebfd fecdb fabcd edb | fdgacbe cefdb cefbgd gcbe
+edbfga begcd cbg gc gcadebf fbgde acbgfd abcde gfcbed gfec | fcgedb cgb dgebacf gc
+fgaebd cg bdaec gdafb agbcfd gdcbef bgcad gfac gcb cdgabef | cg cg fdcagb cbg
+fbegcd cbd adcefb dageb afcb bc aefdc ecdab fgdeca fcdbega | efabcd cedba gadfec cb
+aecbfdg fbg gf bafeg dbefa fcge gcbea fcaegb dgceab fcbdga | gecf egdcabf bgf bfgea
+fgeab ca afcebg bdacfeg cfaedg gcfdb baec bfadeg bafgc acf | gebdcfa ecba ca fadegcb
+dbcfg fgd bdegcaf fgec aegbdf ecdfab fbedc dacgb gdcebf gf | cefg dcbef fcge gbcadfe
+bdfegc cbegaf gecbf dfcage bdacg ed bedf ced adcbefg gebcd | ed bcgafe cdgba cbgef
+egadfb cdbfeg cegd fecab cgb gbdefca cg fgcdab egfdb bfceg | gbdfcae bgc cg cgb
+gcafb gcf dcaebfg ecagb gf abcdeg gaef cafbge fdbac fegbdc | fgae cfgab fg bagce
diff --git a/2021/day08/makefile b/2021/day08/makefile
new file mode 100644
index 0000000..5c81ee3
--- /dev/null
+++ b/2021/day08/makefile
@@ -0,0 +1,2 @@
+all day08.cpp:
+	g++ -std=c++20 -o day08 day08.cpp
diff --git a/2021/utils.h b/2021/utils.h
new file mode 100644
index 0000000..b96f570
--- /dev/null
+++ b/2021/utils.h
@@ -0,0 +1,26 @@
+#ifndef UTILS_H
+#define UTILS_H
+
+void split (std::vector<std::string> &vec, std::string str, std::string del) {
+    auto token = str.find(del);
+    if (token != std::string::npos) {
+        vec.push_back(str.substr(0, token));
+        split(vec, str.substr(token+del.size()), del);
+    } else { vec.push_back(str); }
+}
+
+// trim
+static inline void ltrim(std::string &s) {
+    s.erase(s.begin(), std::find_if(s.begin(), s.end(), [](unsigned char ch) {
+        return !std::isspace(ch);
+    }));
+}
+static inline void rtrim(std::string &s) {
+    s.erase(std::find_if(s.rbegin(), s.rend(), [](unsigned char ch) {
+        return !std::isspace(ch);
+    }).base(), s.end());
+}
+static inline void trim(std::string &s) { ltrim(s); rtrim(s); }
+
+
+#endif