第十一周-判断三角形

#include <stdio.h>#define swap(x,y){x=x+y;y=x-y;x=x-y;}/*下面三个函数都是：是返回1，不是返回0*/int right_triangle(double a,double b,double c); /*判断直角三角形*/int acute_triangle(double a,double b,double c); /*判断锐角三角形*/int obtuse_triangle(double a,double b,double c); /*判断钝角三角形*/int main(){    double a,b,c;   /*三角形的三边*/    scanf("%lf %lf %lf",&a,&b,&c);  /*输入三边*/    /*将三边按照从小到大排好*/    if(a>b)        swap(a,b);    if(a>c)        swap(a,c);    if(b>c)        swap(b,c);    /*根据if判断选择三角形*/    if(acute_triangle(a,b,c))        printf("锐角三角形\n");    else if(right_triangle(a,b,c))        printf("直角三角形\n");    else if(obtuse_triangle(a,b,c))        printf("钝角三角形\n");    return 0;}int acute_triangle(double a,double b,double c){    return(a*a+b*b>c*c);}int right_triangle(double a,double b,double c){    return(a*a+b*b==c*c);}int obtuse_triangle(double a,double b,double c){    return(a*a+b*b<c*c);}