用指针编写函数，交换俩个数

#include<stdio.h>

int main()

void swop(int *p1,int *p2)
{ int num;
num=*p1;
*p1=*p2;
*p2=num;
}
{ void swop(int *p1,int *p2);
int a,b;
int *pointer_1,*pointer_2;
pointer_1=&a;pointer_2=&b;
scanf("%d,%d",&a,&b);
swop(pointer_1,pointer_2);
printf("%d,%d\n"a,b);
return 0;
}
求改正

#include <stdio.h>

    void swop(int *p1, int *p2)
{
    int num;
    num = *p1;
    *p1 = *p2;
    *p2 = num;
}
int main()


{
    int a, b;
    int *pointer_1, *pointer_2;
    pointer_1 = &a;
    pointer_2 = &b;
    scanf("%d,%d", &a, &b);
    swop(pointer_1, pointer_2);
    printf("%d,%d\n", a, b);
    return 0;
}