2024 day 7

2024/7/main-1.cpp

@@ -0,0 +1,46 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+typedef unsigned long long ull;
+
+inline ull testn(vector<int> &ns, ull b) {
+	ull v = ns[0];
+	for (int i = 1; i < ns.size(); i++) {
+		if (b & 1) {
+			v += ns[i];
+		} else {
+			v *= ns[i];
+		}
+		b >>= 1;
+	}
+	return v;
+}
+
+int main() {
+	ios::sync_with_stdio(0);
+	cin.tie(0);
+
+	ull sum = 0;
+	string line;
+	while (getline(cin, line) && !line.empty()) {
+		istringstream l(line);
+		ull n;
+		int a;
+		vector<int> ns;
+		l >> n;
+		l.ignore();
+		while (l >> a) {
+			ns.push_back(a);
+		}
+
+		ull btot = 1 << (ns.size() - 1);
+		for (ull b = 0; b <= btot; b++) {
+			if (testn(ns, b) == n) {
+				sum += n;
+				break;
+			}
+		}
+	}
+
+	cout << sum << '\n';
+}

2024/7/main-2.cpp

@@ -0,0 +1,52 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+typedef unsigned long long ull;
+
+inline ull testn(vector<int> &ns, ull b) {
+	ull v = ns[0];
+	for (int i = 1; i < ns.size(); i++) {
+		switch (b % 3) {
+		case 0:
+			v += ns[i];
+			break;
+		case 1:
+			v *= ns[i];
+			break;
+		case 2:
+			v *= pow(10, (int)log10(ns[i]) + 1);
+			v += ns[i];
+		}
+		b /= 3;
+	}
+	return v;
+}
+
+int main() {
+	ios::sync_with_stdio(0);
+	cin.tie(0);
+
+	ull sum = 0;
+	string line;
+	while (getline(cin, line) && !line.empty()) {
+		istringstream l(line);
+		ull n;
+		int a;
+		vector<int> ns;
+		l >> n;
+		l.ignore();
+		while (l >> a) {
+			ns.push_back(a);
+		}
+
+		ull btot = pow(3, (ns.size() - 1));
+		for (ull b = 0; b <= btot; b++) {
+			if (testn(ns, b) == n) {
+				sum += n;
+				break;
+			}
+		}
+	}
+
+	cout << sum << '\n';
+}