HW2_matrix

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


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;
}

int qsort(int *a, int l, int r, int k)
{
    if (l >= r)
        return -1;
    int q = partition(a, l, r, sizeof(int), compare);
    if (q == k)
        return a[k];
    else if (q > k)
        qsort(a, l, q, k);
    else
        qsort(a, q + 1, r, k);
}

int main()
{
    int m = 0, n = 0, c = 0;
    scanf("%d", &m);
    scanf("%d", &n);
    int** matrix = (int**)malloc(m*sizeof(int));
    for (int i = 0; i < m; i++)
    {
        matrix[i] = (int*)malloc(n*sizeof(int));
        for (int j = 0; j < n; j++)
            scanf("%d", &matrix[i][j]);
    }
    int* ans = (int*)malloc(m*sizeof(int));
    for (int i = 0; i < m; i++)
    {
        scanf("%d", &c);
        ans[i] = qsort(matrix[i], 0, n, c);
    }
    for (int i = 0; i < m; i++)
        printf("%d ", ans[i]);
    return 0;
}