【前缀和】Acwing795.前缀和

Acwing795.前缀和

题解

#include <iostream>
#include <cstdio>

using namespace std;

const int N = 1e5+10;

int a[N];

int main()
{
    int n, m;
    scanf("%d%d",&n,&m);
    int x, y;
    for(int i = 1; i <= n; ++i){
        scanf("%d",&x);
        a[i] = a[i-1] + x;
    }
    while(m -- )
    {
        scanf("%d%d",&x,&y);
        printf("%d\n",a[y] - a[x-1]);
    }
    return 0;
}