LeetCode-Questions/Problem 20 at main · MohdMusaiyab/LeetCode-Questions · GitHub

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class Solution {
public:
    bool isValid(string s) {
        stack<char> st;
        for(int i=0;i<s.length();i++)
        {
            if(s[i]=='{' || s[i]=='('|| s[i]=='[')
            {
                st.push(s[i]);
            }
            else if(st.empty())
            {
                return false;
            }
            else{
                char c=st.top();
                if((s[i]==')' && c=='(') ||(s[i]=='}' && c=='{') || (s[i]==']' && c=='[') )
                {
                    st.pop();
                }
                else{
                    return false;
                }
            }
        }
        if(st.size()!=0)
        {
            return false;
        }
        return true;
    }
};