math — вычисляет много значений с помощью многих арифметических операторов. Переполнение стека

1. #ifndef CALC_H
   #define CALC_Hclass calc
   {
   double numb1;
   double numb2;
   public:
   calc();
   void FUN_SUM();
   void FUN_Subtraction();
   void FUN_Multiplication();
   void FUN_Division();
   void FUN_Power();
   void FUN_Squareroot();
   void FUN_Switch();
   void FUN_Loob();
   
   };
   
   #endif // CALC_H#include "calc.h"#include <iostream>
   #include <cmath>
   using namespace std;
   calc::calc()
   {
   numb1 = 0;
   numb2 = 0;
   }
   void calc::FUN_SUM()
   {
   cout << "Enter number 1 " << endl;
   cin >> numb1;
   cout << "Enter number 2 " << endl;
   cin >> numb2;
   double Result_Of_Sum;
   Result_Of_Sum = numb1+numb2;
   cout << "The result of Sum = " << Result_Of_Sum << endl;}
   
   void calc::FUN_Subtraction()
   {
   cout << "Enter number 1 " << endl;
   cin >> numb1;
   cout << "Enter number 2 " << endl;
   cin >> numb2;
   double Result_Of_Subtraction;
   Result_Of_Subtraction = numb1 - numb2;
   cout << "The result of Subtraction = " << Result_Of_Subtraction << endl;
   }
   void calc::FUN_Multiplication()
   {
   cout << "Enter number 1 " << endl;
   cin >> numb1;
   cout << "Enter number 2 " << endl;
   cin >> numb2;
   double Result_Of_Multiplication;
   Result_Of_Multiplication = numb1*numb2;
   cout << "The result of Multiplication = " << Result_Of_Multiplication << endl;
   
   }
   
   void calc::FUN_Division()
   {
   cout << "Enter number 1 " << endl;
   cin >> numb1;
   cout << "Enter number 2 " << endl;
   cin >> numb2;
   double Result_Of_Division ;
   Result_Of_Division = numb1/numb2;
   cout << "The result of Division = " << Result_Of_Division << endl;
   }
   
   void calc::FUN_Power()
   {
   cout << "Enter number 1 " << endl;
   cin >> numb1;
   cout << "Enter number 2 " << endl;
   cin >> numb2;
   double Result_Of_Power;
   Result_Of_Power = pow(numb1,numb2);
   cout << "The result of Power = " << Result_Of_Power << endl;
   }
   
   void calc::FUN_Squareroot()
   {
   cout << "Enter the tow number you want Square root \n";
   cin >> numb1;
   
   double Result_Of_Square_root;
   Result_Of_Square_root = sqrt(numb1);
   cout << "The result of Square root = " << Result_Of_Square_root << endl;
   }
   void calc::FUN_Switch()
   {
   int S;
   cout << "Enter the number you operator do you want do it  " << endl;
   cout << "1- Addition" << endl;
   cout << "2- Subtraction" << endl;
   cout << "3- Multiplication" << endl;
   cout << "4- Division" << endl;
   cout << "5- Power" << endl;
   cout << "6- Square Root" << endl;
   cout << "7- Exit" << endl;
   cin >> S;
   
   switch (S)
   {
   case 1:
   
   FUN_SUM();
   break;
   
   case 2:
   
   FUN_Subtraction();
   break;
   
   case 3:
   
   FUN_Multiplication();
   break;
   
   case 4:
   
   FUN_Division();
   break;
   
   case 5:
   
   FUN_Power();
   break;
   
   case 6:
   
   FUN_Squareroot();
   break;
   
   default :
   break;
   
   }
   }
   
   void calc::FUN_Loob()
   {
   char L;
   
   do
   {
   
   FUN_Switch();
   
   cout << "Do you want do another operator ( 'y' or 'n'?) \n";
   cin >> L;
   if (L== 'y' || L=='Y' || L=='n' || L=='N')
   
   continue;
   else
   cout << "you are enter roang later\n";
   
   }
   
   while (L == 'Y' || L == 'y' );
   
   }#include <iostream>
   #include "calc.h"using namespace std;
   
   int main()
   {
   cout << "Welcome to my simple Calculator\n";
   calc simple_calc;
   
   simple_calc.FUN_Loob();
   cout << "\n Tank you for use my App :) :) " << endl;
   
   return 0;
   }
   

Мой вопрос заключается в том, как я могу включить пользователь Calc любое значение с помощью операторов, как обычный калькулятор

например 1 + 9 * 8-1 + 5 я хочу, чтобы моя программа делала так, но я не знаю как ?? 🙁 🙁