Envío 6158

Código

import java.util.HashMap;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int n = scanner.nextInt();
        int[][] matrix = new int[n][n];
        HashMap <Integer, Integer> rows = new HashMap<>();
        HashMap <Integer, Integer> columns = new HashMap<>();
        int diagonalLefRight = 0;
        int diagonalRightLeft = 0;
        int magicNumber = 0;
        boolean flag = true;
        int lastIndex = n-1;

        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                if(!rows.containsKey(i)){
                    rows.put(i, 0);
                }

                if(!columns.containsKey(j)){
                    columns.put(j, 0);
                }

                int x = scanner.nextInt();

                rows.put(i, rows.get(i) + x);
                columns.put(j, columns.get(j) + x);

                if(i == 0 && j == lastIndex){
                    magicNumber = rows.get(i);
                }

                if(j == lastIndex){
                    int count = rows.get(i);
                    if(count != magicNumber){
                        flag = false;
                    }
                }

                if(i == lastIndex){
                    int count = columns.get(j);
                    if(count != magicNumber){
                        flag = false;
                    }
                }

                if(i == j){
                    diagonalLefRight += x;
                }

                if(j+i == n-1){
                    diagonalRightLeft +=x;
                }
            }
        }

        if (magicNumber != diagonalLefRight || magicNumber != diagonalRightLeft){
            flag = false;
        }

        if(flag){
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
}