From 72a3388c042f4812e2db33f6d6a1b757392a18a6 Mon Sep 17 00:00:00 2001
From: jacopograndi <jacopo.grandi@outlook.it>
Date: Thu, 6 Jan 2022 18:33:02 +0100
Subject: day08

---
 day08/day08.cpp | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 day08/day08.cpp

(limited to 'day08/day08.cpp')

diff --git a/day08/day08.cpp b/day08/day08.cpp
new file mode 100644
index 0000000..30b818b
--- /dev/null
+++ b/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;
+}
-- 
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