Cool Developer

<pre><code>import java.io.*;
import java.util.Arrays;
import java.util.stream.Collectors;

public class 멘토링 {
 public static void main(String[] args) throws IOException {
 BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
 BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
 String[] temp = br.readLine().split(" ");
 int studentCount = Integer.parseInt(temp[0]);
 int examCount = Integer.parseInt(temp[1]);
 int[][] arrs = new int[examCount][studentCount];

 for(int i =0; i<examCount; i++){
 int[] students = new int[studentCount];
 String[] temp2 = br.readLine().split(" ");
 for(int j=0; j<studentCount; j++){
 students[j] = Integer.parseInt(temp2[j]);
 }
 arrs[i] = students;
 }

 bw.write(solution(arrs, studentCount, examCount));
 bw.flush();
 bw.close();
 br.close();

 }

 private static String solution(int[][] arrs, int studentCount, int examCount) {
 int[][] check = new int[studentCount+1][studentCount+1];
 int answer= 0;
 for(int i =0; i<examCount; i++) {
 for(int j=0; j<studentCount-1; j++){
 int mentor = arrs[i][j];
 for(int k = j+1; k<studentCount; k++){
 int menti = arrs[i][k];
 if(check[menti][mentor] ==0 && check[mentor][menti] ==0){
 check[mentor][menti] =1;
 answer++;
 }else if(check[menti][mentor] ==1){
 check[menti][mentor] =-1;
 check[mentor][menti] = -1;
 answer--;
 }
 }
 }
 }
 return String.valueOf(answer);
 }


}
</code></pre>&nbsp;

멘토링 문제 4중for문

주석을 달면서 한줄씩 인과관계를 따져보면서 코드를 스스로 이해하는게 중요할 것 같아요

3시간 고민해서 풀었습니다.

이건 선택 정렬이 아닌 것 같은데..