标签:bre str log push case and contain 出栈 bool
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.
括号匹配,遍历string,碰到左括号把左括号入栈,碰到右括号出栈,判断出栈的字符和右括号是否匹配。
public class Solution { public boolean isValid(String s) { Stack<Character> stack = new Stack<Character>(); for (int i = 0; i < s.length(); i++) { switch (s.charAt(i)) { case ‘(‘: case ‘{‘: case ‘[‘: stack.push(s.charAt(i)); break; case ‘)‘: if (stack.empty() || stack.pop() != ‘(‘) { return false; } break; case ‘}‘: if (stack.empty() || stack.pop() != ‘{‘) { return false; } break; case ‘]‘: if (stack.empty() || stack.pop() != ‘[‘) { return false; } break; } } if (stack.empty()) { return true; } else { return false; } } }
标签:bre str log push case and contain 出栈 bool
原文地址:http://www.cnblogs.com/yuchenkit/p/7169505.html