// Read  SIZE x SIZE numbers and test if
// they form a magic square http://en.wikipedia.org/wiki/Magic_square
//
// and exits if the same number is read twice
//
// Andrew Taylor - andrewt@unsw.edu.au
// 10/4/13

/*
//  Lo Shu Square
// 4  9  2
// 3  5  7
// 8  1  6
//
// Magic square of primes
//  17  89  71
// 113  59   5
//  47  29 101
*/

#include <stdio.h>

#define SIZE 3

int main(void) {
    int x[SIZE][SIZE];
    int row, column;
    int magicConstant, sum;
    int notMagicSquare;

    // read potential magic square
    printf("Enter %d numbers please:\n", SIZE*SIZE);
    row = 0;
    while (row < SIZE) {
        column = 0;
        while (column < SIZE) {
            if (scanf("%d", &x[row][column]) != 1) {
                printf("Couldn't read enough numbers\n");
                return 0;
            }
            column = column + 1;
        }
        row = row + 1;
    }
    printf("Numbers are:\n");
    // print potential magic square
    row = 0;
    while (row < SIZE) {
        column = 0;
        while (column < SIZE) {
            printf("%d ", x[row][column]);
            column = column + 1;
        }
        printf("\n");
        row = row + 1;
    }

    // sum first row
    magicConstant = 0;
    row = 0;
    while (row < SIZE) {
        magicConstant = magicConstant + x[0][row];
        row = row + 1;
    }

    // check if sum of each row matches sum of first row
    notMagicSquare = 0;
    row = 1;
    while (row < SIZE) {
        sum = 0;
        column = 0;
        while (column < SIZE) {
            sum = sum + x[row][column];
            column = column + 1;
        }
        if (sum != magicConstant) {
            notMagicSquare = 1;
        }
        row = row + 1;
    }

    // check if sum of each columns matches sum of first rowc
    column = 0;
    while (column < SIZE) {
        sum = 0;
        row = 0;
        while (row < SIZE) {
            sum = sum + x[row][column];
            row = row + 1;
        }
        if (sum != magicConstant) {
            notMagicSquare = 1;
        }
        column = column + 1;
    }

    // summing diagonals left as an exercise

    if (notMagicSquare == 0) {
        printf("Is a magic square\n");
    } else {
        printf("Not a magic square\n");
    }
    return 0;
}