sattolo shuffle

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

void sattolo_shuffle(int *a, size_t size)
{
    while (size-- > 1)
    {
        size_t j = rand() % size;
        int tmp = a[j];
        a[j] = a[size];
        a[size] = tmp;
    }
}

#define VLEN 100

int main(void)
{
    int vals[VLEN];
    int matrix[10][10];

    for (size_t i = 0; i < VLEN; i++)
        vals[i] = i + 1;

    sattolo_shuffle(vals, VLEN);
    memcpy(&matrix[0], vals, sizeof(int) * VLEN);

    for (size_t v = 1; v <= 100; v++)
    {
        system("cls");
        for (size_t i = 0; i < 10; i++, printf("\n\n"))
            for (size_t j = 0; j < 10; j++)
            {
                if (matrix[i][j] == v)
                {
                    printf("-%d- ", matrix[i][j]);
                }
                else printf("%d  ", matrix[i][j]);
            }
        Sleep(500);
    }
    return 0;
}