Balanced Brackets

• Time : O(n)
• Space : O(n)

using namespace std;

bool balancedBrackets(string str) {
	vector<char> st;
	unordered_map<char, char> mp{
		{')','('},
		{']','['},
		{'}','{'}
	};
	for(auto& ch : str) {
		if(mp.count(ch)) {
			if(!st.empty() and mp[ch] == st.back()) {
				st.pop_back();
			} else return false;
		} else if(ch == '(' or ch == '{' or ch == '['){
			st.push_back(ch);
		}
	}
  
  return st.empty();
}