Initial commit

2020/puzzle-01-02.cc

@@ -0,0 +1,24 @@
+#include <iostream>
+#include <string>
+#include <vector>
+
+int main(int argc, char **argv) {
+  std::vector<int> vals;
+  for (std::string line; std::getline(std::cin, line);) {
+    int val = std::stoi(line, nullptr, 10);
+    auto size = vals.size();
+    for (std::size_t i = 0; i < size; ++i) {
+      int64_t v1 = vals[i];
+      for (std::size_t j = 0; j < i; ++j) {
+        int64_t v2 = vals[j];
+        if (v1 + v2 + val == 2020) {
+          std::cout << v1 << " * " << v2 << " * " << val << " = "
+                    << v1 * v2 * std::int64_t(val) << "\n";
+        }
+      }
+    }
+    vals.push_back(val);
+  }
+
+  return 0;
+}