1104. Sum of Number Segments (20)

#include <iostream>#include <cstdio>using namespace std;int main(){int n;scanf("%d", &n);double sum = 0, num = 0;int times = 0;for(int i = 0; i < n; ++i){scanf("%lf", &num);sum += num * (i+1)*(n-i);}printf("%.2f", sum);return 0;}