圓的數據類型

圓的數據類型

 

#include <stdio.h>
#include <stdlib.h>
#include "circle.h"
int main()
{
    Pcircle c1;
    c1 = (Pcircle)malloc(sizeof(struct circle));
    c1->x = 0;
    c1->y = 0;
    c1->radius = 5.6;

    printf("%f\n", circle_area(c1));
    printf("%f\n", circumferfence(c1));
    return 0;
}

 

//////////////////////////////////////////////////////

#include "circle.h"
const double pi = 3.1415926;
double circle_area(Pcircle c)
{
    return pi * c->radius * c->radius;
}
//======================================
double circumferfence(Pcircle c)
{
    return 2 * pi * c->radius;
}
////////////////////////////////

#ifndef _CIRCLE_H_
#define _CIRCLE_H_

struct circle
{
    double x;
    double y;
    double radius;
};
typedef struct circle* Pcircle;
double circle_area(Pcircle c);
double circumferfence(Pcircle c);
#endif // _CIRCLE_H_