C语言编写程序：输入任意3线段的长度,判断组成三角形的种类

#include
double triangle(double a,double b,double c)
{
if (a + b > c && b + c > a && a + c > b) return 1;
else return 0;
}
double dengbian(double a,double b,double c)
{
if (a == b && b == c) return 1;
else return 0;
}
double dengyao(double a,double b,double c)
{
if (a == b || b == c || a == c) return 1;
else return 0;
}
double zhijiao(double a,double b,double c)
{
if (a*a + b*b == c*c || b*b + c*c == a*a || a*a + c*c == b*b) return 1;
else return 0;
}
void main()
{
double a,b,c;
printf("请输入三角形的三边:");
scanf("%lf",&a);
scanf("%lf",&b);
scanf("%lf",&c);
if (triangle(a,b,c))
{
if (dengbian(a,b,c))
printf("是等边三角形n");
else if (dengyao(a,b,c) && zhijiao(a,b,c))
printf("等腰直角三角形n");
else if (dengyao(a,b,c))
printf("是等腰三角形n");
else if (zhijiao(a,b,c))
printf("是直角三角形n");
else
printf("一般三角形n");
}
else printf("不能构成三角形n");
}