C语言求两组整数的交集

以下是C语言求两组整数的交集的代码实现：

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

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

int main() {
    int n, m;
    scanf("%d", &n);
    int *a = (int *)malloc(n * sizeof(int));
    for (int i = 0; i < n; i++) {
        scanf("%d", &a[i]);
    }
    scanf("%d", &m);
    int *b = (int *)malloc(m * sizeof(int));
    for (int i = 0; i < m; i++) {
        scanf("%d", &b[i]);
    }
    qsort(a, n, sizeof(int), cmp);
    qsort(b, m, sizeof(int), cmp);
    int *c = (int *)malloc(n * sizeof(int));
    int k = 0;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (a[i] == b[j]) {
                c[k++] = a[i];
                break;
            }
        }
    }
    if (k == 0) {
        return 0;
    }
    qsort(c, k, sizeof(int), cmp);
    for (int i = 0; i < k; i++) {
        printf("%d ", c[i]);
    }
    free(a);
    free(b);
    free(c);
    return 0;
}