백준 2798

for문애서 i + 1, j + 1를 생각하지 못했다.

import java.util.*;

public class Main{
     public static void main(String[] args) {
         // input
         Scanner sc = new Scanner(System.in);
         int N = sc.nextInt();
         int M = sc.nextInt();
         int sum = 0;
         int temp = 0;
         int[] cards = new int[N];
         for (int i = 0; i < N; i++) cards[i] = sc.nextInt();
         
         // logic
         for (int i = 0; i < cards.length; i++) {
             for (int j = i + 1; j < cards.length; j++) {
                 for (int k = j + 1; k < cards.length; k++) {
                     sum = cards[i] + cards[j] + cards[k];              
                     
                     if (temp < sum && sum <= M) temp = sum;
                 }
             }
         }
         
         // output
         System.out.println(temp);
     }   
}

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));
    StringTokenizer st = new StringTokenizer(br.readLine());
    int N = Integer.parseInt(st.nextToken());
    int K = Integer.parseInt(st.nextToken());
    int[] arr = new int[N];

    st = new StringTokenizer(br.readLine());
    for (int i = 0; i < N; i++) arr[i] = Integer.parseInt(st.nextToken());

    int answer = 0;
    int sum = 0;
    for (int i = 0; i < arr.length; i++) {
      for (int j = i + 1; j < arr.length; j++) {
        for (int k = j + 1; k < arr.length; k++) {
          sum = arr[i] + arr[j] + arr[k];
          if (answer < sum && sum <= K) answer = sum;
        }
      }
    }
    System.out.println(answer);
  }
}