Day 1

aoc-1/main.cpp

@@ -0,0 +1,49 @@
+#include <iostream>
+#include <fstream>
+#include <string>
+#include <unordered_set>
+
+int main() {
+	std::ifstream in{"inputs.txt"};
+	
+	/* Part 1 */
+	std::string line;
+	long total = 0;
+
+	while (std::getline(in, line)) {
+		long value = std::stol(line);
+
+		total += value;
+	}
+
+	std::cout << "[Part 1] Total: " << total << std::endl;
+
+
+	/* Part 2 */
+	total = 0;
+
+	std::unordered_set<long> seen_values;
+
+	bool reoccurence_found = false;
+	long first_reocurrence = 0;
+
+	while (!reoccurence_found) {
+		// seek back to start of file, reset EOF flag
+		in.clear();
+		in.seekg(0, std::ios::beg);
+
+		while (std::getline(in, line) && !reoccurence_found) {
+			if (seen_values.find(total) != seen_values.end()) { // if total is already in set
+				first_reocurrence = total;
+				reoccurence_found = true;
+			}
+			else seen_values.insert(total); // add it to set
+
+			long value = std::stol(line);
+
+			total += value;
+		}
+	}
+
+	std::cout << "[Part 2] First reoccurence: " << first_reocurrence << std::endl;
+}