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.
判断给定的字符串是否是合法的成对括号串
class Solution {
public:
bool isPair(char left, char right){
if(left==‘(‘&&right==‘)‘)return true;
if(left==‘{‘&&right==‘}‘)return true;
if(left==‘[‘&&right==‘]‘)return true;
return false;
}
bool isValid(string s) {
stack<int>st;
for(int i=0; i<s.length(); i++){
if(st.empty())st.push(s[i]);
else{
char left=st.top();
if(isPair(left,s[i]))st.pop();
else st.push(s[i]);
}
}
return st.empty();
}
};LeetCode: Valid Parentheses [020],布布扣,bubuko.com
LeetCode: Valid Parentheses [020]
原文：http://blog.csdn.net/harryhuang1990/article/details/25973405