day09 & day10

10 files changed, 402 insertions, 0 deletions

diff --git a/2021/day09/day09 b/2021/day09/day09
new file mode 100755
index 0000000..1e91342
--- /dev/null
+++ b/2021/day09/day09
diff --git a/2021/day09/day09.cpp b/2021/day09/day09.cpp
new file mode 100644
index 0000000..a034659
--- /dev/null
+++ b/2021/day09/day09.cpp
@@ -0,0 +1,101 @@
+#include <iostream>
+#include <fstream>
+#include <string>
+#include <vector>
+#include <algorithm>
+
+#include "../utils.h"
+
+int xytoi (int size, int x, int y) { return size*y + x; }
+int itox (int size, int i) { return i % size; }
+int itoy (int size, int i) { return i / size; }
+bool oob (int sizex, int sizey, int x, int y) {
+	if (x < 0 || y < 0) return true;
+	if (x >= sizex || y >= sizey) return true;
+	return false;
+}
+
+std::vector<std::pair<int, int>> get_dirs() {
+	std::vector<std::pair<int, int>> dirs {
+		{ 1, 0 }, { 0, 1 }, { -1, 0 }, { 0, -1 }
+	};
+	return dirs;
+}
+
+bool is_min (std::vector<int> grid, int size, int i) {
+	int x = itox(size, i);
+	int y = itoy(size, i);
+	for (auto dir : get_dirs()) {
+		int j = xytoi(size, dir.first+x, dir.second+y);
+		if (!oob(size, grid.size()/size, dir.first+x, dir.second+y))
+			if (grid[j] <= grid[i])	
+				return false;
+	}
+	return true;
+}
+
+std::vector<int> flood (std::vector<int> grid, int size, int i) {
+	std::vector<int> visit ;
+	std::vector<int> q { i };
+	while (q.size() > 0) {
+		int x = itox(size, q[0]);
+		int y = itoy(size, q[0]);
+		if (std::find(std::begin(visit), std::end(visit), q[0]) == std::end(visit)) 
+			visit.push_back(q[0]);
+		q.erase(std::begin(q));
+		for (auto dir : get_dirs()) {
+			int j = xytoi(size, dir.first+x, dir.second+y);
+			if (std::find(std::begin(visit), std::end(visit), j) != std::end(visit)) 
+				continue;
+			if (!oob(size, grid.size()/size, dir.first+x, dir.second+y)) {
+				if (grid[j] < 9) {
+					q.push_back(j);
+				}
+			}
+		}
+	}
+	return visit;
+}
+
+int main (int argc, char * argv[]) {
+	std::string raw;
+	std::getline(std::ifstream(argv[1]), raw, '\0');
+	std::vector<std::string> lines;
+	split(lines, raw, "\n");
+
+	int size = 0;
+	std::vector<int> grid;
+	for (std::string line : lines) {
+		if (line.size() == 0) continue;
+		size = 0;
+		for (char c : line) {
+			grid.push_back(std::stoi(std::string { c } ));
+			size++;
+		}
+	}
+
+	std::cout << "lowpoints: ";
+	std::vector<int> lows;
+	int sum = 0;
+	for (std::size_t i=0; i<grid.size(); i++) {
+		if (is_min(grid, size, i)) {
+			std::cout << "(" << itox(size, i) << " " << itoy(size, i) << "), ";
+			sum += grid[i]+1;
+			lows.push_back(i);
+		}
+	}
+
+	std::cout << std::endl;
+	std::cout << "sum of risk: " << sum << std::endl;
+
+	std::vector<int> isles;
+	for (auto low : lows) {
+		auto visit = flood(grid, size, low);
+		isles.push_back(visit.size());
+	}
+	std::sort(std::begin(isles), std::end(isles), std::greater<int>());
+
+	int res = isles[0] * isles[1] * isles[2];
+	std::cout << "three largest basins multiplied: " << res << std::endl;
+	return 0;
+}
diff --git a/2021/day09/day09_input.txt b/2021/day09/day09_input.txt
new file mode 100644
index 0000000..c064a7b
--- /dev/null
+++ b/2021/day09/day09_input.txt
@@ -0,0 +1,100 @@
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diff --git a/2021/day09/day09_input_ez.txt b/2021/day09/day09_input_ez.txt
new file mode 100644
index 0000000..6dee4a4
--- /dev/null
+++ b/2021/day09/day09_input_ez.txt
@@ -0,0 +1,5 @@
+2199943210
+3987894921
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+8767896789
+9899965678
diff --git a/2021/day09/makefile b/2021/day09/makefile
new file mode 100644
index 0000000..18a7e4a
--- /dev/null
+++ b/2021/day09/makefile
@@ -0,0 +1,2 @@
+all day09.cpp:
+	g++ -std=c++20 -o day09 day09.cpp
diff --git a/2021/day10/day10 b/2021/day10/day10
new file mode 100755
index 0000000..e3b93c6
--- /dev/null
+++ b/2021/day10/day10
diff --git a/2021/day10/day10.cpp b/2021/day10/day10.cpp
new file mode 100644
index 0000000..4fad4ca
--- /dev/null
+++ b/2021/day10/day10.cpp
@@ -0,0 +1,88 @@
+#include <iostream>
+#include <fstream>
+#include <vector>
+#include <stack>
+#include <string>
+#include <algorithm>
+
+#include "../utils.h"
+
+char map (char a) {
+	if (a == '(') return ')';
+	if (a == '[') return ']';
+	if (a == '{') return '}';
+	if (a == '<') return '>';
+	return 'A';
+}
+
+bool match (char a, char b) {
+	if (a == '(' && b == ')') return true;
+	if (a == '[' && b == ']') return true;
+	if (a == '{' && b == '}') return true;
+	if (a == '<' && b == '>') return true;
+	return false;
+}
+
+int score (char a) {
+	if (a == ')') return 3;
+	if (a == ']') return 57;
+	if (a == '}') return 1197;
+	if (a == '>') return 25137;
+	return 0;
+}
+
+long score (std::string str) {
+	long s = 0;
+	for (char c : str) {
+		s *= 5;
+		s += (c == ')' ? 1 : 0);
+		s += (c == ']' ? 2 : 0);
+		s += (c == '}' ? 3 : 0);
+		s += (c == '>' ? 4 : 0);
+	}
+	return s;
+}
+
+bool check (std::string line, std::string &out) {
+	std::stack<char> stack;
+	for (char c : line) {
+		if (c == '(' || c == '[' || c == '{' || c == '<') {
+			stack.push(c);
+		} else {
+			if (!match(stack.top(), c)) {
+				out.push_back(c);
+				return true;
+			} else stack.pop();
+		}
+	}
+	while (!stack.empty()) {
+		out.push_back(map(stack.top()));
+		stack.pop();
+	}
+	return false;
+}
+
+int main (int argc, char *argv[]) {
+	std::string raw;
+	std::getline(std::ifstream(argv[1]), raw, '\0');
+	std::vector<std::string> lines;
+	split(lines, raw, "\n");
+
+	std::vector<long> repairs;
+	int sum = 0;
+	for (auto line : lines) {
+		if (line.size() == 0) continue;
+		std::string rep;
+		bool corrupt = check(line, rep);
+		if (corrupt) sum += score(rep[0]);
+		else {
+			repairs.push_back(score(rep));
+			std::cout << score(rep) << " " << rep << std::endl;
+		}
+	}
+	std::cout << "corrupt score: " << sum << std::endl;
+	std::sort(std::begin(repairs), std::end(repairs));
+	std::cout << "repairs score: " << repairs[(repairs.size()-1)/2] << std::endl;
+
+	return 0;
+}
diff --git a/2021/day10/day10_input.txt b/2021/day10/day10_input.txt
new file mode 100644
index 0000000..eec53e5
--- /dev/null
+++ b/2021/day10/day10_input.txt
@@ -0,0 +1,94 @@
+({<{({([<<{<[<<><>><<>>](<()()>)><{{{}<>}}<<<>{}>[<>[]]>>}{[<<[]{}>[<>()]>[(()[])]]<{{<><>}[[]<>]}{<
+[(<[[([[(([<{{[]{}}([][])}<<{}[]>([]{})>><{<()()><[][]>}{[()]<()[]>}>]<{({()()}){[{}[]][<>()]}}[{[{}<>]
+{{(<[[(<<<(<<[{}{}]{<>()}><{[]{}}([]{})>>([([][]){{}<>}][<()<>>[(){}]]))<{<(<>())[{}<>]>{{[]{}}<<>{}>}}({<
+<([({[<[(([[<(()<>){[]<>}><<(){}>{()()}>]](<(({}[]){[][]})<{<>())[<>[]]>>{{{()<>}{(){}}}{[<>()]<{}[]>}
+<(((<{<(<{{[[[()<>]{[]()}]][{<()[]><<>{}>}]}}[<{[{[][]}[<><>]]}{{{(){}}[<>()]}{[[]()]{<>[]}}}>{[({{}
+{{({[({(({{[<[{}()]([]<>)><<{}()>[<>[]]>]<<{[]{}}([]<>)>{{<>}{<>{}}}}}{{<<[]<>>{<>()}>}<({[]<>}
+(([{[(<(<[[(([()[]][{}()])(([][])<{}<>>))]]>)[<(<{{<<><>>(<>[])}<([]<>)[[]{}]>}((<{}[]>[<><>]){{[
+{{[<<{<<(<([<<[]()>[[][]]>{[()[]]<()[]>}]){(<(<>{})([])>{<(){}>{<>()]}){[<[]()><<>()>](([][
+((<{[{{(<<[(<{<>{}}[<>[]]>{<{}<>>{{}[]}})]>><{([<(<>())[{}()]>{<<>{}>{[]{}}}><([[]()]<[]<>>)(<[]>{()()})>)}>)
+{<({{{(<[([<{(<>[])<()[]>}([[]]([]{}))>])[{{[([]){[]{}}]}}{[[{(){}}{<>{}}][[(){}]]]<([<>{}]{{}<>})(
+([([{{{[[<<[[(()[])<<><>>]{({}[])}]((([]{})<<>>)({[]<>}[<>[]]))>{(({<>()})([{}[]]<()<>>)){[
+{[<(({[<<{{{[({}[]){<>()}]{[()()]{[]()}}}[{<<><>>{<>[]}}<{()()}<()>>]}({<(<><>)[()[]]>([{}()])}{[(<>())(()
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diff --git a/2021/day10/day10_input_ez.txt b/2021/day10/day10_input_ez.txt
new file mode 100644
index 0000000..b1518d9
--- /dev/null
+++ b/2021/day10/day10_input_ez.txt
@@ -0,0 +1,10 @@
+[({(<(())[]>[[{[]{<()<>>
+[(()[<>])]({[<{<<[]>>(
+{([(<{}[<>[]}>{[]{[(<()>
+(((({<>}<{<{<>}{[]{[]{}
+[[<[([]))<([[{}[[()]]]
+[{[{({}]{}}([{[{{{}}([]
+{<[[]]>}<{[{[{[]{()[[[]
+[<(<(<(<{}))><([]([]()
+<{([([[(<>()){}]>(<<{{
+<{([{{}}[<[[[<>{}]]]>[]]
diff --git a/2021/day10/makefile b/2021/day10/makefile
new file mode 100644
index 0000000..038dc5d
--- /dev/null
+++ b/2021/day10/makefile
@@ -0,0 +1,2 @@
+all day10.cpp:
+	g++ -std=c++20 -o day10 day10.cpp