标签：style blog color os io 使用 ar for div
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.
思路：使用栈记录匹配过程。依次遍历s，若当前字符s[i]为‘(‘、‘{‘、‘[‘之一，则将s[i]入栈；否则，取栈顶元素匹配当前字符，若不匹配，返回FALSE，若匹配，继续匹配下一个字符。若s合法，最终栈将为空。
1 class Solution { 2 public: 3 bool isValid( string s ) { 4 stack<char> brackets; 5 for( size_t i = 0; i != s.size(); ++i ) { 6 if( s[i] == ‘(‘ || s[i] == ‘{‘ || s[i] == ‘[‘ ) { 7 brackets.push( s[i] ); 8 } else { 9 if( brackets.empty() || !check( brackets.top(), s[i] ) ) { return false; } 10 brackets.pop(); 11 } 12 } 13 return brackets.empty(); 14 } 15 private: 16 inline bool check( char achar, char si ) { 17 return ( achar == ‘(‘ && si == ‘)‘ ) || ( achar == ‘{‘ && si == ‘}‘ ) || ( achar == ‘[‘ && si == ‘]‘ ); 18 } 19 };
标签：style blog color os io 使用 ar for div
原文地址：http://www.cnblogs.com/moderate-fish/p/3959431.html
