2024 day 11

2024/11/main-1.cpp

@@ -0,0 +1,35 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+typedef unsigned long long ull;
+
+int main() {
+	ios::sync_with_stdio(0);
+	cin.tie(0);
+
+	int n;
+	vector<ull> stones;
+	while (cin >> n) {
+		stones.push_back(n);
+	}
+
+	for (int i = 0; i < 75; i++) {
+		for (int x = 0; x < stones.size(); x++) {
+			if (stones[x] == 0) {
+				stones[x] = 1;
+			} else {
+				int nd = log10(stones[x]) + 1;
+				if (nd % 2 == 0) {
+					ull l = pow(10, nd / 2);
+					stones.insert(stones.begin() + x + 1, stones[x] % l);
+					stones[x] /= l;
+					x++;
+				} else {
+					stones[x] *= 2024;
+				}
+			}
+		}
+	}
+
+	cout << stones.size() << '\n';
+}

2024/11/main-2.cpp

@@ -0,0 +1,42 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+typedef unsigned long long ull;
+
+ull getn(int i, ull n) {
+	static map<pair<int, ull>, ull> m;
+	if (m.contains({i, n})) {
+		return m[{i, n}];
+	}
+
+	ull ret;
+	if (i == 0) {
+		ret = 1;
+	} else if (n == 0) {
+		ret = getn(i - 1, 1);
+	} else {
+		int nd = log10(n) + 1;
+		if (nd % 2 == 0) {
+			ull l = pow(10, nd / 2);
+			ret = getn(i - 1, n % l) + getn(i - 1, n / l);
+		} else {
+			ret = getn(i - 1, n * 2024);
+		}
+	}
+
+	m[{i, n}] = ret;
+	return ret;
+}
+
+int main() {
+	ios::sync_with_stdio(0);
+	cin.tie(0);
+
+	int n;
+	ull ret = 0;
+	while (cin >> n) {
+		ret += getn(75, n);
+	}
+
+	cout << ret << '\n';
+}