lab2_1

/*  determines if a numerical square magic (sum of elems in each column
 *  equally sum of elems in each row and equally sum of elems
 *  in main diagonal) or not magic                                      */

#include <stdio.h>
int isMagic(void);

main()
{
    FILE *ofp;

    ofp = fopen("output.txt", "w");
    if (isMagic() == 0)
        fprintf(ofp, "%s\n", "NO");
    else
        fprintf(ofp, "%s\n", "YES");

    fclose(ofp);

    return 0;
}

int isMagic(void)
{
    int i, j;
    FILE *ifp;
    int size, sum = 0, diag = 0, line = 0;
    char square[10][10];
    char col[10];

    ifp = fopen("input.txt", "r");
    fscanf(ifp, "%d\n", &size);

    for (i = 0; i < size; i++)
        for (j = 0; j < size; j++)
            fscanf(ifp, "%d", &square[i][j]);


    for (j = 0; j < size; j++) {
        sum += square[0][j];
        col[j] = 0;
    }

    for (i = 0; i < size; i++) {
        for (j = 0; j < size; j++) {
            line += square[i][j];
            col[j] += square[i][j];
            if (i == j)
                diag += square[i][j];
        }
        if (line != sum)
            return 0;
        else
            line = 0;
    }

    for (j = 0; j < size; j++) {
        if (col[j] != sum)
            return 0;
    }

    if (diag != sum)
        return 0;

    fclose(ifp);
    return 1;
}