Restructured project and updated day 3

2020/days/day9.cpp

@@ -0,0 +1,87 @@
+/*******************************************************************************
+ *
+ * Copyright (c) 2020 Gnarwhal
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files(the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ *******************************************************************************/
+
+#include <vector>
+#include <string>
+#include <iostream>
+#include <fstream>
+
+#include "../misc/types.hpp"
+#include "../misc/print.hpp"
+
+auto find_sum(usize index, std::vector<u64> xmas) {
+	for (auto i = index - 25; i < index - 1; ++i) {
+		for (auto j = i + 1; j < index; ++j) {
+			if (xmas[i] + xmas[j] == xmas[index]) {
+				return true;
+			}
+		}
+	}
+	return false;
+}
+
+auto day9() -> void {
+	auto xmas = std::vector<u64>();
+	auto line = std::string();
+	auto file = std::ifstream("inputs/day9.input");
+	while (getline(file, line)) {
+		xmas.push_back(std::stoll(line));
+	}
+
+	auto invalid = u64(0);
+	for (auto i = usize(25); i < xmas.size(); ++i) {
+		if (!find_sum(i, xmas)) {
+			print((invalid = xmas[i]));
+			break;
+		}
+	}
+	
+	auto head_index = 0;
+	auto tail_index = 1;
+	auto sum        = xmas[0] + xmas[1];
+	while (sum != invalid) {
+		if (sum < invalid) {
+			sum += xmas[++tail_index];
+		} else if (head_index + 1 < tail_index) {
+			sum -= xmas[head_index];
+			++head_index;
+		} else {
+			head_index = tail_index + 1;
+			tail_index = head_index + 1;
+			sum        = xmas[head_index] + xmas[tail_index];
+		}
+	}
+	auto min = xmas[tail_index];
+	auto max = xmas[tail_index];
+	for (auto i = head_index; i < tail_index; ++i) {
+		if (xmas[i] < min) {
+			min = xmas[i];
+		} else if (xmas[i] > max) {
+			max = xmas[i];
+		}
+	}
+	print((min + max));
+}