다른 풀이 방식(set을 이용한 중복제거)

import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {
	
	public static int Solution(int n, int[][] arr) {
		Set<Integer> set = new HashSet<>();
		int max = 0;
		int answer = 0;
		for(int i = 0 ; i < n ; i++) {
			for(int j = 0 ; j < 5 ; j++) {
				for(int k = 0 ; k < n ; k++) {
					if(i!=k) {
						if(arr[i][j] == arr[k][j]) {
						set.add(k);
						}
					}
				}
			} 
			System.out.println(set);
			if(max < set.size()) {
				max = set.size();
				answer = i+1;
			} 
			set.clear();
		}
		return answer;
	}
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		
		int[][] arr = new int[n][5];
		for(int i = 0 ; i < n ; i++) {
			for(int j = 0 ; j < 5 ; j++) {
				arr[i][j] = sc.nextInt();
			}
		}
		System.out.println(Solution(n,arr));
	} 
}