У меня есть do-while l oop, который должен остановиться, если будет введено что-либо, кроме чисел 1, 2, 3 или 4, но я получу бесконечное l oop, если уберу cin >> choicenum условие из условия l oop или программа останавливается. Как это исправить, чтобы программа автоматически возвращалась к выбору?
#include <iostream>
#include <fstream>
#include <cmath>
#include <limits>
using namespace std;
int choicenum;
float num3, num4, num5, num6, num7, num8, conerslt, sphererslt, octrslt, distrslt, FindVolCone (float, float), num1, num2;
float FindVolSphere (float), FindAreaOct (float), Finddisttwopoint (float, float, float, float);
void dispVolCone (float, float, float), dispVolSphere (float, float), dispAreaOct (float, float), dispdisttwopoint (float, float, float, float, float);
const long double PI = acos(-1);
int main()
{
do
{
// Give the user their options
cout << "This program can calculate the following things: " << endl;
cout << "The volume of a cone, " << endl;
cout << "The volume of a sphere, " << endl;
cout << "The area of an octagon, " << endl;
cout << "Or the distance between two points. " << endl;
// Prompt the user to make a choice
cout << "For the volume of a cone, please enter the number 1. " << endl << "For the volume of a sphere, please enter 2. " << endl;
cout << "For the area of an octagon, please enter 3. " << endl << "For the distance between two points, please enter 4. " << endl;
cout << "If you would like to close this program, enter any other key." << endl;
cin >> choicenum;
switch (choicenum)
{
case 1:
cout << "Please enter the radius of the cone: " << endl;
cin >> num1;
cout << "Please enter the height of the cone: " << endl;
cin >> num2;
conerslt = FindVolCone (num1, num2);
dispVolCone (num1, num2, conerslt);
break;
case 2: // Calculate volume of sphere;
cout << "Please enter the radius of the sphere: " << endl;
cin >> num3;
sphererslt = FindVolSphere (num3);
dispVolSphere (num3, sphererslt);
break;
case 3: // Calculate area of octagon;
cout << "Please enter one side of the octagon: " << endl;
cin >> num4;
octrslt = FindAreaOct (num4);
dispAreaOct (num4, octrslt);
break;
case 4: // Calculate distance between two points;
cout << "Please enter the x value, then y value of the first point: " << endl;
cin >> num5;
cin >> num6;
cout << "Please enter the x value, then y value of the second point: " << endl;
cin >> num7;
cin >> num8;
distrslt = Finddisttwopoint (num5, num6, num7, num8);
dispdisttwopoint (num5, num6, num7, num8, distrslt);
break;
default: // Kill program;
cout << "Thank you for using this program. " << endl;
break;
}
} while (cin >> choicenum && choicenum >= 1, choicenum <= 4);
return 0;
}
float FindVolCone (float radnumcone, float heightnumcone)
{
float VolCone;
VolCone = PI * pow(radnumcone, 2) * (heightnumcone / 3);
return VolCone;
}
void dispVolCone (float radnumcone, float heightnumcone, float VolCone)
{
cout << "The volume of a cone with radius " << radnumcone << " and height " << heightnumcone << " is " << VolCone << ". " << endl;
}
float FindVolSphere (float radnumsphere)
{
float VolSphere;
VolSphere = (4 / 3) * PI * pow(radnumsphere, 3);
return VolSphere;
}
void dispVolSphere (float radnumsphere, float VolSphere)
{
cout << "The volume of a sphere with radius " << radnumsphere << " is " << VolSphere << ". " << endl;
}
float FindAreaOct (float sidenumoct)
{
float AreaOct;
AreaOct = 2 * (1 + sqrt(2)) * pow(sidenumoct,2);
return AreaOct;
}
void dispAreaOct (float sidenumoct, float AreaOct)
{
cout << "The area of an octagon with side length " << sidenumoct << " is " << AreaOct << ". " << endl;
}
float Finddisttwopoint (float xvalone, float yvalone, float xvaltwo, float yvaltwo)
{
float disttwopoint;
disttwopoint = sqrt(pow((xvaltwo - xvalone),2) + pow((yvaltwo - yvalone),2));
return disttwopoint;
}
void dispdisttwopoint (float xvalone, float yvalone, float xvaltwo, float yvaltwo, float disttwopoint)
{
cout << "The distance between point (" << xvalone << ", " << yvalone << ") and (" << xvaltwo << ", " << yvaltwo << ") is " << disttwopoint << ". " << endl;
}