[백준] 수들의 합 2 2003 - JAVA

문제

https://www.acmicpc.net/problem/2003

2003번: 수들의 합 2

 

 

코드

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

public class Main {	 

	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		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=0;i<n;i++) {
			arr[i] = Integer.parseInt(st.nextToken());
		}
		
		int l = 0, r = 0;
		int sum = 0;
		int count = 0;
		while(l<=r && r<=n) {
			if(sum == m) {
				count++;
			}
			if(sum >= m) {
				sum = sum - arr[l];
				l++;
			}
			else {
				sum = sum + arr[r];
				r++;
			}
		}
		
		if(sum == m)
			count++;
		
		System.out.print(count);
		
	}
	
	
}