Restructured project and updated day 3

2020-12-11 09:24:22 -08:00 · 2020-12-11 09:24:22 -08:00 · 44b298b12e
commit 44b298b12e
parent 372300ccb0
29 changed files with 245 additions and 104 deletions
--- a/2020/days/day8.cpp
+++ b/2020/days/day8.cpp
@ -0,0 +1,111 @@
+/*******************************************************************************
+ *
+ * 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"
+
+enum OpCode { Acc, Jmp, Nop };
+struct Op{ OpCode code; i32 num; bool executed; };
+auto extract_op(const std::string & string) -> Op {
+	auto op = Op{ Nop, 0 };
+	auto op_code_str = string.substr(0, 3);
+	     if (string.substr(0, 3) == "acc") { op.code = Acc; }
+	else if (string.substr(0, 3) == "jmp") { op.code = Jmp; }
+	else if (string.substr(0, 3) == "nop") { op.code = Nop; }
+
+	op.num = std::stoi(string.substr(string.find(" ") + 1, string.size() - 4));
+
+	return op;
+}
+
+struct State{ u32 isp; i32 acc; };
+
+auto execute(State & state, std::vector<Op> & ops) -> void {
+	switch (ops[state.isp].code) {
+		case Acc: ops[state.isp].executed = true; state.acc += ops[state.isp].num; ++state.isp; break;
+		case Jmp: ops[state.isp].executed = true; state.isp += ops[state.isp].num;              break;
+		case Nop: ops[state.isp].executed = true;                                  ++state.isp; break;
+	}
+}
+
+auto attempt_swap(State & state, std::vector<Op> & ops) -> bool {
+	if (ops[state.isp].code == Jmp) {
+		ops[state.isp].code = Nop;
+	} else if (ops[state.isp].code == Nop) {
+		ops[state.isp].code = Jmp;
+	} else {
+		return false;
+	}
+
+	auto local_state = state;
+	ops[state.isp].executed = false;
+	while (local_state.isp < ops.size() && !ops[local_state.isp].executed) {
+		execute(local_state, ops);
+	}
+	if (local_state.isp >= ops.size()) {
+		state = local_state;
+		return true;
+	} else if (ops[state.isp].code == Jmp) {
+		ops[state.isp].code = Nop;
+	} else if (ops[state.isp].code == Nop) {
+		ops[state.isp].code = Jmp;
+	}
+
+	return false;
+}
+
+auto day8() -> void {
+	auto ops = std::vector<Op>();
+	{
+		auto line = std::string();
+		auto file = std::ifstream("inputs/day8.input");
+		while (getline(file, line)) {
+			ops.push_back(extract_op(line));
+		}
+	}
+	
+	auto state = State{ 0, 0 };
+	while (!ops[state.isp].executed) {
+		execute(state, ops);
+	}
+	print(state.acc);
+
+	for (auto & op : ops) { op.executed = false; }
+
+	state = State{ 0, 0 };
+	for (;;) {
+		if (attempt_swap(state, ops)) {
+			print(state.acc);
+			break;
+		}
+		execute(state, ops);
+	}
+}