백준 11659번(Java)

import java.io.*;
import java.util.*;

public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder sb = new StringBuilder();
		StringTokenizer st = new StringTokenizer(br.readLine());
		
		int N = Integer.parseInt(st.nextToken());
		int M = Integer.parseInt(st.nextToken());
		int arr[] = new int[N+1];
		
		st = new StringTokenizer(br.readLine());
		for(int i=1; i<=N; i++) {
			arr[0] = 0;
			arr[i] = arr[i-1] + Integer.parseInt(st.nextToken());
		}
		
		for(int i=0; i<M; i++) {
			st = new StringTokenizer(br.readLine());
			int start = Integer.parseInt(st.nextToken());
			int end = Integer.parseInt(st.nextToken());
			sb.append(arr[end]-arr[start-1]).append('\n');
		}
		
		System.out.println(sb);
	}
}