2024 day 22

2024/22/main-1.cpp

@@ -0,0 +1,27 @@
+#include "../../include/aoc.hpp"
+#include <bits/stdc++.h>
+using namespace std;
+
+ll mp(ll n, ll o) { return (n ^ o) % 16777216; }
+
+int main() {
+	ios::sync_with_stdio(0);
+	cin.tie(0);
+
+	vector<int> secrets;
+	int n;
+	while (cin >> n) {
+		secrets.push_back(n);
+	}
+
+	ll count = 0;
+	for (ll s : secrets) {
+		for (int i = 0; i < 2000; i++) {
+			s = mp(s * 64, s);
+			s = mp(s / 32, s);
+			s = mp(s * 2048, s);
+		}
+		count += s;
+	}
+	cout << count << '\n';
+}

2024/22/main-2.cpp

@@ -0,0 +1,55 @@
+#include "../../include/aoc.hpp"
+#include <bits/stdc++.h>
+using namespace std;
+
+size_t h(vector<char> &v) {
+	size_t ret = 0;
+	for (int i = 0; i < 4; i++) {
+		ret += v[v.size() - 1 - i] << (i * 8);
+	}
+	return ret;
+}
+
+ll mp(ll n, ll o) { return (n ^ o) % 16777216; }
+
+int main() {
+	ios::sync_with_stdio(0);
+	cin.tie(0);
+
+	vector<int> secrets;
+	ll n;
+	while (cin >> n) {
+		secrets.push_back(n);
+	}
+
+	unordered_map<size_t, int> m;
+	for (ll s : secrets) {
+		char sp = s % 10;
+		vector<char> ss;
+		unordered_set<size_t> done;
+		for (int i = 0; i < 2000; i++) {
+			char oldsp = sp;
+			s = mp(s * 64, s);
+			s = mp(s / 32, s);
+			s = mp(s * 2048, s);
+			sp = s % 10;
+			ss.push_back(sp - oldsp);
+			if (ss.size() >= 4) {
+				auto hss = h(ss);
+				if (done.contains(hss)) {
+					continue;
+				}
+				done.insert(hss);
+				m[hss] += sp;
+			}
+		}
+	}
+
+	int mx = 0;
+	for (auto n : m) {
+		if (n.second > mx) {
+			mx = n.second;
+		}
+	}
+	cout << mx << '\n';
+}