C++ Program to check for balanced parentheses in an expression using stack.

BalancedParentheses.cpp

/*
  C++ Program to check for balanced parentheses in an expression using stack.
  Given an expression as string comprising of opening and closing characters
  of parentheses - (), curly braces - {} and square brackets - [], we need to 
  check whether symbols are balanced or not. 
*/
#include<iostream>
#include<stack>
#include<string>
using namespace std;
// Function to check whether two characters are opening 
// and closing of same type. 
bool ArePair(char opening,char closing)
{
	if(opening == '(' && closing == ')') return true;
	else if(opening == '{' && closing == '}') return true;
	else if(opening == '[' && closing == ']') return true;
	return false;
}
bool AreParanthesesBalanced(string exp)
{
	stack<char>  S;
	for(int i =0;i<exp.length();i++)
	{
		if(exp[i] == '(' || exp[i] == '{' || exp[i] == '[')
			S.push(exp[i]);
		else if(exp[i] == ')' || exp[i] == '}' || exp[i] == ']')
		{
			if(S.empty() || !ArePair(S.top(),exp[i]))
				return false;
			else
				S.pop();
		}
	}
	return S.empty() ? true:false;
}

int main()
{
	/*Code to test the function AreParanthesesBalanced*/
	string expression;
	cout<<"Enter an expression:  "; // input expression from STDIN/Console
	cin>>expression;
	if(AreParanthesesBalanced(expression))
		cout<<"Balanced\n";
	else
		cout<<"Not Balanced\n";
}

`def balancedBrackets(string):
#remove all invalid characters. This is optional by the way.If your string only contains [{()}]. You don't have to change input string in any
way
string = [x for x in string if x in '[{()}]]']

stack = []

for char in string:
	if char in '([{':
		stack.append(char)
	else:
		if len(stack) == 0  or not arePair(stack[-1], char):
			return False
		else:
			stack.pop()
if len(stack) == 0:return True
return `False`

def arePair(opening,closing):
if opening == '(' and closing == ')':return True
elif opening == '[' and closing == ']': return True
elif opening == '{' and closing == '}':return True
return False
`

https://github.com/BaseMax/ValidationParentheses

Solution Using JavaScript: you can also check the whiteboard and test from here:

class MultiBracketValidation {
  constructor() {
    this.stack = new Stack();
    this.opening = ["{", "(", "[", "<"];
    this.closing = ["}", ")", "]", ">"];
  }
  checkForValidation(input) {
    for (const char of input) {
      if (this.isOpening(char)) {
        this.stack.push(char);
      } else if (this.isClosing(char)) {
        if (
          this.stack.isEmpty() ||
          !this.isPair(this.stack.peek().value, char)
        ) {
          return false;
        } else {
          this.stack.pop();
        }
      }
    }
    return this.stack.isEmpty();
  }
  isOpening(char) {
    return this.opening.indexOf(char) >= 0;
  }
  isClosing(char) {
    return this.closing.indexOf(char) >= 0;
  }
  isPair(opening, closing) {
    return this.closing.indexOf(closing) === this.opening.indexOf(opening);
  }
}

Hey, I am a beginner in programming, and tried to implement the pseudo code shared in the video using C++, can you guys share the reviews about the coding style.

bool checkBalancedParenthesis(string exp){
    stack<char> s;
    int n = exp.length();
    for(int i=0; i<n; i++){
        if (exp[i] == '{' || exp[i] == '(' || exp[i] == '['){
            s.push(exp[i]);
        }
        else if(exp[i] == '}' || exp[i] == ')' || exp[i] == ']'){
            if (s.empty())
            return false;
            switch (s.top())
            {
            case '(':
                if (exp[i] == ')')
                    {s.pop();
                    break;}
                else{
                    return false;
                }
            case '{':
                if (exp[i] == '}')
                    {s.pop();
                    break;}
                else{
                    return false;
                }
            case '[':
                if (exp[i] == ']')
                    {s.pop();
                    break;}
                else{
                    return false;
                }
            }
        }    
    }
    return s.empty()?true:false;
}

Hey, I am a beginner in programming, and tried to implement the pseudo code shared in the video using C++, can you guys share the reviews about the coding style.

bool checkBalancedParenthesis(string exp){
    stack<char> s;
    int n = exp.length();
    for(int i=0; i<n; i++){
        if (exp[i] == '{' || exp[i] == '(' || exp[i] == '['){
            s.push(exp[i]);
        }
        else if(exp[i] == '}' || exp[i] == ')' || exp[i] == ']'){
            if (s.empty())
            return false;
            switch (s.top())
            {
            case '(':
                if (exp[i] == ')')
                    {s.pop();
                    break;}
                else{
                    return false;
                }
            case '{':
                if (exp[i] == '}')
                    {s.pop();
                    break;}
                else{
                    return false;
                }
            case '[':
                if (exp[i] == ']')
                    {s.pop();
                    break;}
                else{
                    return false;
                }
            }
        }    
    }
    return s.empty()?true:false;
}

If you are waiting for the mentors to reply then they ain't goint to reply and apart from that yeah coding style looks good