HW2_qsort_simple

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#define _CRT_SECURE_NO_WARNINGS

int * generate(int* n)
{
    int * arr = (int *)malloc((*n) * sizeof(int));
    for (int i = 0; i < *n; ++i)
    {
        arr[i] = rand();
    }
    return arr;
}

int compare(void *a, void *b)
{
    return(*(int*)a - *(int*)b);
}

typedef int(*PCmp)(void *, void*);

int partition(void * a, int l, int r, int sz, PCmp cmp)
{
    char *carr = (char *)a;
    int i = l - 1;
    void *ptmp = malloc(sz);
    for (int j = l; j < r - 1; ++j)
    {
        if (cmp(carr + j*sz, carr + (r-1)*sz) <= 0)
        {
            i++;
            memcpy(ptmp, carr + i*sz, sz);
            memcpy(carr + i*sz, carr + j*sz, sz);
            memcpy(carr + j*sz, ptmp, sz);
        }
    }
    memcpy(ptmp, carr + (i + 1)*sz, sz);
    memcpy(carr + (i + 1)*sz,carr + (r-1)*sz, sz);
    memcpy(carr + (r - 1)*sz, ptmp, sz);
    return i + 1;
}

void qsort(int *a, int l, int r)
{
    if (l >= r)
        return;
    int q = partition(a, l, r, sizeof(int), compare);
    qsort(a, l, q);
    qsort(a, q + 1, r);
}

int main()
{
    srand(time(NULL));

    int n = 0, t = 0;
    scanf("%d", &n);
    int* arr = generate(&n);

    qsort(arr, 0, n);
    /*for (int i = 0; i < n; i++)
    {
        printf("%d ", arr[i]);
    }*/
    for (int i = 1; i < n; i++)
    {
        if (arr[i - 1] > arr[i])
        {
            printf("ERROR %d %d\n", arr[i - 1], arr[i]);
            t++;
        }
    }
    if (!t)
    {
        printf("OK\n");
    }
    return 0;
}