struct hypot typedef

C语言定义结构体：struct 结构体名称{域定义}；

但是为了使用方便用：typedef struct {域定义}；结构体名称；

示例：

#include<stdio.h>#include<math.h>struct Point{double x,y;};double dist(struct Point a,struct Point b){    return hypot(a.x - b.x,a.y - b.y);}int main(){    Point a,b;    a.x = 1,a.y = 1;    b.x = 2,b.y = 2;    double c = dist(a,b);    printf("%lf\n",c);    return 0;}

#include<stdio.h>#include<math.h>typedef struct {double x,y;}Point; //多了typedef，可以像int ,double,float用double dist(Point a,Point b)       //少了struct{    return hypot(a.x - b.x,a.y - b.y);}int main(){    Point a,b;    a.x = 1,a.y = 1;    b.x = 2,b.y = 2;    double c = dist(a,b);    printf("%lf\n",c); //输出1.414214    return 0;}