Java Magic Square: A n x n matrix that is filled with the numbers 1, 2, 3,.... n

Question

Java Magic Square:
A n x n matrix that is filled with the numbers 1, 2, 3,.... n^2 is a magic square if the sum of the elements in each row, in each column, and in the two diagonals is the same value.
I need to write an application that gets 16 values as user input, in any order. Store these values in an ArrayList. When the numbers are put into a square, this would be a 4x4 two-dimensional array.

Then test the following features to see if the numbers entered make a magic square:

1. Does each of the numbers 1 - 16 occur in the input? Note: I must perform this check from the ArrayList using the "contains" method.
2. Are the sums of the rows, columns, and diagonals equal to each other? If possible: when you store the number in the ArrayList, store it in a two-dimensional array too.

Here’s a sample run (user input in bold): Enter the numbers 1 - 16 in any order: 12 13 2 7 6 3 16 9 15 10 5 4 1 8 11 14 - You found a magic square! -
Here’s another example: This time it’s not going to work: Enter the numbers 1 - 16 in any order: 2 3 7 10 9 16 4 5 12 8 1 15 14 11 13 6 - The numbers you have entered are not a magic square.
And one more that won’t work: Enter the numbers 1 - 16 in any order: 12 13 2 7 6 3 16 9 16 10 5 4 1 8 11 14 - The numbers you have entered are not a magic

Here's an example where n 4: 16 32 13 5 10 11 8 9 67 12 4 15 14 Let's look to see if it's a magic square. 34 34 8 34 12 34 34 34 10 11 6 15 14 7 4 34 34 34 34

Explanation / Answer

I have made it for N, which can be taken as a input from the user.

If you do not wish it to be dynamic then assign N=4, and remove the code for taking N as input.

following code will check if the values entered are magic or not

-----------------------------------------------------------MagicSquare.java----------------------------------------------------

// JAVA program to check whether a given

// matrix is magic matrix or not

import java.io.*;

import java.util.Scanner;

class MagicSquare {

static int N;

static boolean isMagicSquare(int mat[][])

{

// calculate the sum of

// the prime diagonal

int sum = 0;

for (int i = 0; i < N; i++)

sum = sum + mat[i][i];

// For sums of Rows

for (int i = 0; i < N; i++) {

int rowSum = 0;

for (int j = 0; j < N; j++)

rowSum += mat[i][j];

// check if every row sum is

// equal to prime diagonal sum

if (rowSum != sum)

return false;

}

// For sums of Columns

for (int i = 0; i < N; i++) {

int colSum = 0;

for (int j = 0; j < N; j++)

colSum += mat[j][i];

// check if every column sum is

// equal to prime diagonal sum

if (sum != colSum)

return false;

}

return true;

}

// driver program to

// test above function

public static void main(String[] args)

{

Scanner sc = new Scanner(System.in);

System.out.println("please enter the size of square");

N = sc.nextInt();

int[][] Matrix = new int[N][N];

System.out.println("Enter the numbers 1 - "+N*N+" in any order");

for(int i=0;i<N;i++) {

for(int j=0;j<N;j++) {

Matrix[i][j] = sc.nextInt();

}

}

if (isMagicSquare(Matrix))

System.out.println("You found a magic square!");

else

System.out.println("The numbers you have entered are not a magic");

}

}

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