[leetcode] 20/22 Vaild parentheses/generate parentheses
Givenastringcontainingjustthecharacters'(',')','{','}','['and']',determineiftheinputstringisvalid.Aninputstringisvalidif:Openbracketsmustbeclosedbythesametypeofbrackets.Openbracketsmustbeclosedintheco