#include<stdio.h>
#include<math.h>
void main()
{
    float *x, *y;
    void change(float *x, float *y);
    printf("input x,y:\n");scanf("%f%f", x, y);
    change(x, y);
    printf("%f,%f", *x, *y);
}
void change(float *x,float *y)
{
    float s=*x, p=*y;
    s = pow((s) * (s) + (p) * (p), 1.0 / 2);
    //p = pow(tan((p) / (s)), -1);
    p=tan(p/s);
    p=p/1;
    *x = s;*y = p;
}