Magic Square in C

#include <stdio.h>
#include <stdlib.h>

void magic_square(int[][100], int);
int verify_magic_square(int[][100], int);
void show(int[][100], int);

int main()
{
    int n, mat[100][100];

do
    {
        printf("enter order of square matrix(must be an odd): ");
        scanf("%d", &n);

if (n % 2 == 0)
            printf("Must enter odd number!!\n");
    } while (n % 2 == 0);

magic_square(mat, n);

show(mat, n);

if (verify_magic_square(mat, n) == 1)
        printf("\nIt is a magic square");
    else
        printf("\nIt is not a magic square");
    return 0;
}

void magic_square(int sq[][100], int n)
{
    int i, j, num;

for (i = 0; i < n; ++i)
        for (j = 0; j < n; ++j)
            sq[i][j] = 0;

i = 0;
    j = n / 2;
    num = 1;
    do
    {
        if (sq[i][j] == 0)
            sq[i][j] = num;

i--;
        j++;

if (i < 0 && (j >= 0 && j < n))
        {
            i = n - 1;
        }
        else if ((i >= 0 && i < n) && j >= n)
        {
            j = 0;
        }
        else if ((i >= 0 && i < n) && (j >= 0 && j < n) && sq[i][j] != 0)
        {
            i += 2;
            j--;
        }
        else if (i < 0 && j >= n)
        {
            i = 1;
            j = n - 1;
        }
        num++;
    } while (num <= n * n);
}

int verify_magic_square(int sq[][100], int n)
{
    int i, j, sum = 0, tmp = 0;
    for (i = 0; i < n; ++i)
        sum += sq[0][i];

// checking for row sum
    for (i = 1; i < n; ++i)
    {
        for (j = 0; j < n; ++j)
            tmp += sq[i][j];
        if (tmp != sum)
            return 0;
        tmp = 0;
    }

// checking for column sum
    for (j = 0; j < n; ++j)
    {
        for (i = 0; i < n; ++i)
            tmp += sq[i][j];
        if (tmp != sum)
            return 0;
        tmp = 0;
    }

// checking for right diagonal
    for (i = 0; i < n; ++i)
        tmp += sq[i][i];
    if (tmp != sum)
        return 0;

// checking for left diagonal
    tmp = 0;
    for (i = 0; i < n; ++i)
        tmp += sq[i][n - i - 1];
    if (tmp != sum)
        return 0;

return 1;
}

void show(int sq[][100], int n)
{
    int i, j;
    for (i = 0; i < n; ++i)
    {
        for (j = 0; j < n; ++j)
            printf("%3d ", sq[i][j]);
        printf("\n");
    }
}

Output1:

enter order of square matrix(must be an odd): 5

17 24 1 8 15

23 5 7 14 16

4 6 13 20 22

10 12 19 21 3

11 18 25 2 9

It is a magic square

Output2:

enter order of square matrix(must be an odd): 4

Must enter odd number!!

enter order of square matrix(must be an odd): 3

8 1 6

3 5 7

4 9 2

It is a magic square

Magic Square in C..