Using STL to verify Brackets or Parentheses Combination in an Expression

Write a program to test whether the pairs and orders of ““, “”, “(“, “)”, “[“, “]” in the expression string exp are correct.



given string = " [[[{}()]]]


Given string of brackets is balanced

Check for Balanced Brackets in an expression


  • Make an empty character stack and traverse the characters in the string one by one.
  • If an open bracket is encountered, it should be pushed into the stack.
  • If a close bracket is encountered, match it with its open bracket counterpart at the top of the stack.
  • If the match is successful, remove the character from the stack.
  • If the match is a failure, RETURN FALSE.
  • Return TRUE if the stack is empty; otherwise, return FALSE.

2)Check Balanced parentheses

Below is the implementation:

#include <bits/stdc++.h>
using namespace std;
// function which checkOpen brackets
bool checkOpenBracket(char character,
                      map<char, char> bracketMap)
    map<char, char>::iterator itr = bracketMap.begin();
    // Traverse the bracket map till end of it
    while (
        != bracketMap.end()) { // if the value of the given
                               // key is equal to given
                               // character then return true
        if (itr->second == character) {
            return true;
        // increment the iterator to next key
    return false;
// function which checks the balanced bracket
bool checkBalancedBracket(string str)
{ // initializing a stack which stores the characters
    stack<char> charstack;
    // initializing a map which stores the open and closed
    // brackets and parenthesis
    map<char, char> parantheses_map;
    // initalizing the map with open and closed bracket
    // characters
    parantheses_map['}'] = '{';
    parantheses_map[')'] = '(';
    parantheses_map[']'] = '[';
    // Traverse the string
    for (int i = 0; i < str.size(); i++) {
        // checking if it is open bracket
        if (checkOpenBracket(str[i], parantheses_map))
        if (parantheses_map.find(str[i])
            != parantheses_map.end()) {
            if (charstack.empty())
                // Return false if the character stack is empty
                return false;
            if (
                != parantheses_map[str[i]]) {
                return false;
    if (charstack.size() > 0)
        return false;
        return true;
int main()
{ // passing brackets string to checkBalancedBracket
  // function
    if (checkBalancedBracket("{{[[]]()}}"))
        cout << "Given string of brackets is balanced"
             << endl;
        cout << "Given string og brackets is not balanced"
             << endl;

    return 0;


Given string of brackets is balanced

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