feat: update 1104

Author: treeforest

PAT/1104/main.cpp

@@ -0,0 +1,14 @@
+#include <iostream>
+using namespace std;
+
+int main() {
+	int n;
+	cin >> n;
+	double sum = 0.0, tmp;
+	for (int i = 1; i <= n; i++) {
+		cin >> tmp;
+		sum += (tmp * i * (n - i + 1));
+	}
+	printf("%.2f\n", sum);
+	return 0;
+}