up在线求助！

#include<iostream>

int d(int x,int y,int z); 

using namespace std;

int main(void)

{

    int a;

    int b;

    int c;

//int y;

cout<<"输入三边长以判断："<<endl;

cin>>a>>b>>c;

//cin>>y;

cout<<"" <<endl; 

d(a,b,c);

}

int d(int x,int y,int z)

{

if (x*x+y*y=z*z)

{

cout<<x*y/2<<endl;

}

else if (x^2+z^2=y^2)

{

cout<<x*z/2<<endl;

}

else if (y^2+z^2=x^2)

{

cout<<y*z/2<<endl;

}

else

{

cout<<"这不是直角三角形！"<<endl; 

}

}