函数指针练习

#include <stdio.h>
#include <string.h>
#define M 5
void exc(int *a,int *(*p)(int *), int *(*q)(int *))
{
    int c, *m, *n; 
    m = p(a);
    n = q(a);
    c = *m;
    *m = *n;
    *n = c;
}
int *max(int *a)
{
    int *t;
    t = a;
    for (int i = 1; i < M; ++i)
    {
        if (*t < *(t + 1))
        {
            t = t + 1;
        }
    }
    printf("max = %d\n", *t);
    return t;   
}
int *min(int *a)
{
    int *t;
    t = a;
    for (int i = 1; i < M; ++i)
    {
        if (*t > *(t + i))
        {
            t += i;
        }
    }
    printf("min = %d\n", *t);
    return t;
}
int main(int argc, char const *argv[])
{
    int a[M];
    for (int i = 0; i < M; ++i)
    {
        scanf("%d", &a[i]);
    }
    int *(*p)(int *), *(*q)(int *);
    p = min;
    q = max;
    exc(a, p, q);
    for (int i = 0; i < M; ++i)
    {
        printf("%d ", a[i]);
    }
    return 0;
}