Parenthesis Checker

 Parenthesis Checker

Given an expression string x. Examine whether the pairs and the orders of “{“,”}”,”(“,”)”,”[“,”]” are correct in exp.
For example, the function should return 'true' for exp = “[()]{}{[()()]()}” and 'false' for exp = “[(])”

Example 1:

Input:
{([])}
Output: 
true
Explanation: 
{ ( [ ] ) }. Same colored brackets can form 
balaced pairs, with 0 number of 
unbalanced bracket.

Example 2:

Input: 
()
Output: 
true
Explanation: 
(). Same bracket can form balanced pairs, 
and here only 1 type of bracket is 
present and in balanced way

Solution:

bool ispar(string x)

{

    // Your code here

    stack<char> s;

    for (int i = 0; i < x.size(); i++)

    {

        if (x[i] == '(' || x[i] == '{' || x[i] == '[')

            s.push(x[i]);

        else

        {

            if (s.empty())

                return false;

            char c = s.top();

            if (x[i] == ')' && c != '(')

                return false;

            else if (x[i] == '}' && c != '{')

                return false;

            else if (x[i] == ']' && c != '[')

                return false;

            s.pop();

        }

    }

    return s.empty();

}