标签:leetcode解题报告 面试题 算法 java
Given a string containing just the characters ‘(‘ and ‘)‘, find the length of the longest valid (well-formed) parentheses substring.public class Solution {
    public int longestValidParentheses(String s) {
        if(s==null||s.length()==0) {
            return 0;
        }
        int start     = -1;
        int maxLength = 0;
        Stack stack   = new Stack();
        for(int i=0;i<s.length();i++) {
            if(s.charAt(i)=='(') {
                stack.push(i);
            } else {
                if(!stack.empty()) {
                    stack.pop();
                    if(stack.empty()==true) {
                        maxLength = Math.max(i - start , maxLength);
                    } else {
                        maxLength = Math.max(i - (int)stack.peek() , maxLength);
                    }
                } else {
                    start = i;
                }
            }
        }
    
        return maxLength;
    }
}Leetcode Longest Valid Parentheses 结题报告
标签:leetcode解题报告 面试题 算法 java
原文地址:http://blog.csdn.net/worldwindjp/article/details/39460161