int * f (int*s,int*t)//int * means that the return value is an int pointer, f is the function name int * s, and int * t means that two int pointers are passed in, that is, the addresses of two plastic variables are passed in;

int k;

if(*s< *t)

{k=*s; *s=*t; *t=*k; }//directly change the pointed space value through the address

return s

This problem is that the address of the variable is passed in by the function, and the operation in the function is to find the original variable through the address and operate it.