第1个回答 2020-05-25
在调用函数时多加一个计数引用就行了。
例如有返回值的函数求解一元二次方程的解
double Calculate2(double a,double b,double c,double& _count)//a,b,c为系数，_count
//为计数参数
{
double judge;
double solution1,solution2;
judge = pow(b,2) - 4 * a * c;
if(judge < 0&&_count==0)
{
cout << "the equation has not any solution!" << endl;
return 0;
}
else if(judge == 0 && _count==0)
{
solution1 = -b / (2 * a);
cout << "this equation has one solution!" << '\n';
return solution1;
}
else if(judge > 0)
{
solution1 = (-b + sqrt(judge) ) / (2 * a);
solution2 = (-b - sqrt(judge)) /(2 * a);
if(_count == 0)cout << "this equation has two solutions!" << '\n';
if(_count == 0)//第一次调用函数返回值给solution1
{
_count++;
return solution1; //其他时候返回值给solution2
}
return solution2;
}
}