From 19be9f44dbecdde03662be2248eda5b739d67038 Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Wed, 25 Dec 2024 00:40:50 +0100
Subject: Day 24 2024 still don't know how I managed to solve this

---
 2024/24/day24a.cpp | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 2024/24/day24a.cpp

(limited to '2024/24/day24a.cpp')

diff --git a/2024/24/day24a.cpp b/2024/24/day24a.cpp
new file mode 100644
index 0000000..231b206
--- /dev/null
+++ b/2024/24/day24a.cpp
@@ -0,0 +1,88 @@
+/* Use clean.sh on the input first */
+
+#include <algorithm>
+#include <cstdint>
+#include <iostream>
+#include <map>
+#include <queue>
+#include <ranges>
+#include <set>
+#include <sstream>
+#include <string>
+#include <string_view>
+#include <vector>
+using namespace std;
+
+int8_t state[36*36*36];
+
+int d(char x) { return x >= 'a' && x <= 'z' ? x-'a' : 26+x-'0'; }
+int index(char a, char b, char c) { return d(c) + 36 * (d(b) + 36 * d(a)); }
+int z(int i) { return index('z', (i/10)+'0', (i%10)+'0'); }
+
+enum class Op { AND, OR, XOR };
+
+class Gate {
+public:
+	int x, y, z;
+	Op op;
+
+	bool ready() const {
+		return state[x] != -1 && state[y] != -1;
+	}
+
+	bool operate() const { /* Returns true if the operation flips a bit */
+		auto oldstate = state[z];
+		switch (op) {
+		case Op::AND:
+			state[z] = state[x] & state[y];
+			break;
+		case Op::OR:
+			state[z] = state[x] | state[y];
+			break;
+		case Op::XOR:
+			state[z] = state[x] ^ state[y];
+			break;
+		}
+		return oldstate != state[z];
+	}
+};
+
+Op make_op(char c) {
+	switch (c) {
+	case '&': return Op::AND;
+	case '|': return Op::OR;
+	default: return Op::XOR;
+	}
+}
+
+int main() {
+	vector<Gate> gates;
+	fill(state, state + 36*36*36, -1);
+	string line;
+
+	while (getline(cin, line) && line != "")
+		state[index(line[0], line[1], line[2])] = line[5]-'0';
+
+	while (getline(cin, line))
+		gates.push_back(Gate {
+			.x = index(line[0], line[1], line[2]),
+			.y = index(line[6], line[7], line[8]),
+			.z = index(line[13], line[14], line[15]),
+			.op = make_op(line[4])
+		});
+
+	for (bool flag = true; flag; ) {
+		flag = false;
+		for (auto g : gates)
+			if (g.ready())
+				flag = flag || g.operate();
+	}
+
+	int64_t result = 0;
+	for (int64_t i = 0, j = 1; state[z(i)] != -1; i++, j *= 2)
+		result += (int64_t)state[z(i)] * j;
+
+	cout << result << endl;
+
+	return 0;
+}
-- 
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