[백준] 11659 - JAVA

📃문제

🔎문제 분석하기

	1	2	3	4	5
배열 a	5	4	3	2	1
배열 b	5	9	12	14	15

예제 입력에서 1,3이면, b[3]-b[0] = 12이고,
2,4이면 b[4]-b[1] = 9
5,5이면 b[5]-b[4] = 1

b[i] = b[i-1] + a[i]

💻코드

BufferReader 이용

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Doit01_03 {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        int suNo = Integer.parseInt(st.nextToken());
        int quizNo = Integer.parseInt(st.nextToken());
        long[] s = new long[suNo+1];
        st = new StringTokenizer(br.readLine());
        for(int i = 1;i<=suNo; i++){
            s[i] = s[i-1] + Integer.parseInt(st.nextToken());
        }
        for(int q=0;q<quizNo; q++){
            st = new StringTokenizer(br.readLine());
            int i = Integer.parseInt(st.nextToken());
            int j = Integer.parseInt(st.nextToken());
            System.out.println(s[j]-s[i-1]);
        }
    }
}

Scanner 이용

import java.io.IOException;
import java.util.Scanner;
;

public class Main {
    public static void main(String[] args){
       Scanner sc = new Scanner(System.in);
       int a = sc.nextInt();
       int b = sc.nextInt();

       int []arr = new int[a+1];
       for(int i=1;i<=a;i++){
           arr[i]+=arr[i-1]+sc.nextInt();
       }

       for(int q=0;q<b;q++){
           int i = sc.nextInt();
           int j = sc.nextInt();

           System.out.println(arr[j]-arr[i-1]);
       }
    }
}