Given a string containing just the characters '('
, ')'
, '{'
, '}'
, '['
and ']'
, determine if the input string is valid.
The brackets must close in the correct order, "()"
and "()[]{}"
are all valid but "(]"
and "([)]"
are not.
Tags:
Solution:
class Solution { public: bool isValid(string s) { stack<char> stk; for(int i=0;i<s.size();i++){ char c=s[i]; if(c=='('||c=='['||c=='{'){ stk.push(c); }else if(c==')'||c=='}'||c==']'){ if(stk.empty())return false; else{ char c2=stk.top(); stk.pop(); if((c2=='('&&c!=')')||(c2=='{'&&c!='}')||(c2=='['&&c!=']'))return false; } } } return stk.empty(); } };