1104. Sum of Number Segments (20)

AC代码

#include<stdio.h>#include<vector> using namespace std;vector<double> a;int main(){int n;scanf("%d",&n);double sum=0;for(int i=0;i<n;i++){double temp;scanf("%lf",&temp);a.push_back(temp);}for(int i=0;i<n;i++){sum+=a[i]*(n-i)*(i+1);}printf("%.2lf\n",sum);}

原先写的，和上面的应该一样，但就是一个测试点不过

#include<stdio.h>#include<vector> using namespace std;vector<double> a;int main(){int n;scanf("%d",&n);double sum=0;for(int i=0;i<n;i++){double temp;scanf("%lf",&temp);a.push_back(temp);}for(int i=0;i<n/2;i++){sum+=(a[i]+a[n-1-i])*(n-i)*(i+1);}if(n%2==1){sum+=a[n/2]*(n-n/2)*(n/2+1);}printf("%.2lf\n",sum);}