程序递归进入无限循环[关闭]

Question

我编写了一个程序，它接受两个输入——汽车的面积和摩擦系数——作为参数，然后计算阻力。

如果用户输入了无效的摩擦值（必须是0.2 <= friction <= 0.5），else 条件会正常工作。

但是，当我输入有效的摩擦值时，它会进入一个无限循环，并且永远不会给我任何错误。

这是我的代码。

double area, friction;

cout << "lutfen surtunen yuzeyi giriniz: \n";
cin >> area;

cout << "lutfen surtunme katsayisini giriniz: \n";
cin >> friction;

calc_force(velocity, area, friction);

// My function

void calc_force(int velocity, double area, double friction)
{
    double force;
    double seccade = friction;
    if(0.2 <= seccade && seccade <= 0.5 ) { // if  statement does not work
        force = (0.0615)*area*friction*velocity*velocity;
        cout << "Velocity\t\t Drag Coefficien\t\t Area\t\t Force\n";
        cout << "\t\t" << velocity << "\t\t" << seccade << "\t\t" << area << "\t\t" << force << "\n";
        velocity+=5;

        if(velocity>40) return ;

        cout << "lutfen surtunme katsayisini giriniz: \n";
        cin >> friction;
        cout << "lutfen surtunen yuzeyi giriniz: \n";
        cin >> area;
        calc_force(velocity, area, friction);
    } else { // this works
        cout << "lutfen surtunme katsayisini dogru giriniz: \n";
        cin >> friction;
        cout << "lutfen surtunen yuzeyi giriniz: \n";
        cin >> area;
        calc_force(velocity, area, friction);
    }
}

velocity 定义为const int。当我调用和定义函数时，我有int friction 到double friction。我已按照以下建议更正了其他数据类型。我使函数递归，因为我希望它重复。

Answer 1

试试这个：

void calc_force(int velocity, double area, double friction){
    double force;
    double seccade = friction;
    if(0.2 <= seccade && seccade <= 0.5 ){ // if  statement does not work
        force = (0.0615)*area*friction*velocity*velocity;
        cout<<"Velocity\t\t Drag Coefficien\t\t Area\t\t Force\n";
        cout<<"\t\t"<<velocity<<"\t\t"<<seccade<<"\t\t"<<area<<"\t\t"<<force<<"\n";

        velocity+=5;
    }

    if (velocity > 40 ) {
        return;
    } else {
        cout<<"lutfen surtunme katsayisini giriniz: \n";
        cin>>friction;
        cout<<"lutfen surtunen yuzeyi giriniz: \n";
        cin>>area;
        calc_force(velocity, area, friction);
    }
}

这既包含了参数的更改，也将递归移到了 if 语句之外。这确保了一个基本案例是可访问的，并且应该为您提供您正在寻找的功能。