Answer to Question #193556 in C++ for Rose

Question

Use the C++ precedence rules to remove any unnecessary parenthesis from the following expressions :

A. ((a* b)) + (c * d))

B.   ((a* b) / (c * d))

C.   ((a + b) + ((c / (d + e)) * f))

D.  (((a + b) / (c + d))* (e + f))

E.   ((-a + b) <= (c * d)) && ((a + b) >= (c - d))

Answer 1

#include <bits/stdc++.h> 
#include<iostream>
#include <stdio.h>
#include <string>
#include <set>
#include <stack>
using namespace std;




int Count;




std::string CheckExp(std::string InputStr, int tempCount) 
{
  std::set<char> Op = {'+', '-', '*', '/'};




  std::string expression;
  std::set<char> op;
  Count = tempCount;




  while (true) {
    if (InputStr[Count] == '(') 
	{
      expression += CheckExp(InputStr, Count + 1);
    } else if (InputStr[Count] == ')') {
     if ((InputStr[Count + 1] != '*') && (InputStr[Count + 1] != '/'))  return expression;
	  else 
	  {
        if ((op.find('+') == op.end()) && (op.find('-') == op.end())) 	return expression;
		else 															return '(' + expression + ')';
      }
    } 
	else 
	{
      char temp = InputStr[Count];
      expression = expression + temp;




      if (Op.find(temp) != Op.end())  op.insert(temp);
    }




    Count++;




    if (Count >= InputStr.size()) break;
  }




  return expression;
}




int main() 
{
  std::string s1("((a* b)) + (c * d))");
  std::cout << CheckExp(s1, 0)<<endl;




  std::string s2("((a* b) / (c * d))");
  std::cout << CheckExp(s2, 0)<<endl;


  std::string s3("((a + b) + ((c / (d + e)) * f))");
  std::cout << CheckExp(s3, 0)<<endl;




  std::string s4("(((a + b) / (c + d))* (e + f)");
  std::cout << CheckExp(s4, 0)<<endl;
  
 
  std::string s5("((-a + b) <= (c * d)) && ((a + b) >= (c - d))");
  std::cout << CheckExp(s5, 0)<<endl;
  
  return 0;
}