[알고리즘] 한빈이와 Spot Mart

https://swexpertacademy.com/main/code/problem/problemDetail.do?contestProbId=AW8Wj7cqbY0DFAXN

SW Expert Academy

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Collections;
import java.util.StringTokenizer;
 
public class Solution {
    static StringBuilder sb = new StringBuilder();
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;
         
        st = new StringTokenizer(br.readLine());
        int T = Integer.parseInt(st.nextToken());
        for (int testCase = 1; testCase <= T; testCase++) {
            st = new StringTokenizer(br.readLine());
            int N = Integer.parseInt(st.nextToken());
            int M = Integer.parseInt(st.nextToken());
             
            int[] snacks = new int[N];
            st = new StringTokenizer(br.readLine());
            for (int i = 0; i < N; i++) {
                snacks[i] = Integer.parseInt(st.nextToken());
            }
             
            Arrays.sort(snacks);
            sb.append("#").append(testCase).append(" ");
            int maxWeight = Integer.MIN_VALUE;
            int start = 0;
            int end = N-1;
            out: while (start < end) {
                int sumWeight = snacks[start] + snacks[end];
                if (sumWeight > M) {
                    end--;
                } else if (sumWeight == M) {
                    maxWeight = M;
                    break out;
                } else {
                    maxWeight = Math.max(maxWeight, sumWeight);
                    start++;
                }
            }
            if (maxWeight == Integer.MIN_VALUE) {
                maxWeight = -1;
            }
            sb.append(maxWeight).append("\n");
        }
        System.out.println(sb);
    }
}

나의 풀이

- 이중 포인터를 활용하면 되는 문제

- start와 end가 같아질 때까지 while 조건문을 설정해주면 된다.

- start++인데 start--라고 적는 실수를 했었다.