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