JAVA 代码

import java.util.Scanner;
import java.io.BufferedInputStream;

class Main{
    private int N = 100010;

    public static void main(String[] args){

        Scanner in = new Scanner(new BufferedInputStream(System.in));

        int n = in.nextInt();
        int m = in.nextInt();
        //存放接收进来的数组
        int[] arr = new int[n + 1];
        //存放前缀和数组
        int[] newArr = new int[n + 1];
        //为了下面写代码方便将它设为0
        newArr[0] = 0;
        //原数组初始化
        for(int i = 1; i < n + 1; i++)
            arr[i] = in.nextInt();
        //前缀和数组初始化
        for(int i = 1; i < n + 1; i++)
            newArr[i] = newArr[i - 1] + arr[i];
        //读下面的数 计算
        while(m-- > 0){
            int l = in.nextInt();
            int r = in.nextInt();
            System.out.println(newArr[r] - newArr[l - 1]);
        }
    }
}