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.
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class Solution { public: bool isValid(string s) { stack<char> store; for (auto c : s) { if (c == ‘(‘ || c == ‘{‘ || c == ‘[‘) store.push(c); else { if (store.empty()) return false; if (c == ‘)‘ && store.top() == ‘(‘){ store.pop(); } else if (c == ‘}‘ && store.top() == ‘{‘){ store.pop(); } else if (c == ‘]‘ && store.top() == ‘[‘){ store.pop(); } else return false; } } return store.empty(); } };
原文：http://www.cnblogs.com/wxquare/p/5929837.html