异常处理2

#include<iostream>
#include<cmath>
#include<stdexcept>
using namespace std;
double area(double a,double b,double c) throw (invalid_argument){
if(a<=0||b<=0||c<=0)
throw invalid_argument("the side length should be positive");
if(a+b<=c||b+c<=a||c+a<=b)
throw invalid_argument("the side length should fit the triangle inequation");
double s=(a+b+c)/2;
return sqrt(s*(s-a)*(s-b)*(s-c));
}
int main()
{
double a,b,c;
cout<<"Please input the side length of a triangle: ";
cin>>a>>b>>c;
try{
double s=area(a,b,c);
cout<<"Area: "<<s<<endl;
}catch (exception &e){
cout<<"Error: "<<e.what()<<endl;
}
return 0;
}