题目描述
前缀和
C++ 代码
#include<iostream>
using namespace std;
const int N = 100010;
int s[N];
int main()
{
int n, m;
cin >> n >> m;
for (int i = 1; i <= n; i ++)
{
cin >> s[i];
s[i] += s[i - 1];
}
while (m --)
{
int l, r;
cin >> l >> r;
cout << s[r] - s[l - 1] << endl;
}
return 0;
}