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

struct data
{
char name[10];
int math;
};

void swap(struct data *p1,struct data *p2)
{
struct data tmp;
tmp=*p1;
*p1=*p2;
*p2=tmp;
};

int main()
{
struct data student[2]={{"john",100},{"tom",90}};
swap(&student[0],&student[1]);
printf("%s got %d\n",student[1].name,student[1].math);
return 0;
}