Answer 1

/* 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