HW2_shell_sort

#include <cstdio>
#include <cstdlib>
#include <ctime>

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

void ins_sort(int* arr, int k, int n)
{
    int x = 0, q = 0;
    for (int i = 0; i < k; i++)
    {
        for (int j = i; j < n; j += k)
        {
            x = arr[j];
            for (q = j - k; q >= 0 && arr[q] > x; q -= k)
                arr[q + k] = arr[q];
            arr[q + k] = x;
        }
    }

}

void shell_sort(int* arr, int n)
{
    int i = n / 2;
    while (i >= 1)
    {
        ins_sort(arr, i, n);
        i /= 2;
    }
}

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

    int N = 0, t = 0;
    scanf("%i", &N);
    int* arr = generate(&N);
    shell_sort(arr, N);
    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;
}