[003] 구간합 구하기 BJ11659

https://www.acmicpc.net/problem/11659

11659번: 구간 합 구하기 4

 

package Chapter1;
import java.util.*;

public class BJ11659 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        int[] arr = new int[n];
        int[] sumArr = new int[n+1];   // 합배열 생성

        for (int i=0; i<n; i++) {
            arr[i] = sc.nextInt();
        }

		// 합배열 첫번째는 0
        sumArr[0] = 0;
        for (int i=1; i<=n; i++) {
            sumArr[i] = sumArr[i-1] + arr[i-1];
        }

        for (int k=0; k<m; k++) {
            int i = sc.nextInt();
            int j = sc.nextInt();
            System.out.println(sumArr[j] - sumArr[i-1]); // i~j 합읜 sumArr[i] - sumArr[j-1]
        }
    }
}