"Leetcode-Interview algorithm classic-java Implementation" "032-longest Valid parentheses (maximum effective bracket)"

"032-longest Valid parentheses (maximum effective bracket)" "leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index" Original Question

Given A string containing just the characters ‘(‘ ‘)‘ and, find the length of the longest valid (well-formed) parenthe SES substring.
"(()"for, the longest valid parentheses substring "()" are, which has length = 2.
Another example ")()())" is, where the longest valid parentheses substring "()()" are, which has length = 4.

Main Topic

Given a string that contains only the parentheses number, the maximum number of valid parentheses is obtained.

Thinking of solving problems

Using stacks to implement

Code Implementation

Algorithm implementation class

ImportJava.Util.Deque;ImportJava.Util.LinkedList;ImportJava.Util.Stack; PublicClass Solution { Publicint longestvalidparentheses (Strings) {//To record the position of the opening and closing brackets to be matched        Stack<Integer>St= New Stack<>(); IntMax = 0; for (int i= 0; I<S.Length (); I++) {//If the current character is a closing parenthesis, and the record stack is non-empty, and the previous character is an opening parenthesis            if(s.CharAt (i)== ' ) ' && !St.IsEmpty ()&&S.CharAt (St.Peek ())== ' (') {///left bracket out stackSt.Pop ();//Seek maximum value                Max =Math.Max(Max+ N-(St.IsEmpty ())? -1: St.Peek ())); }//In other cases, put characters into the stack            Else{St.push (i); }        }return Max; }}

Evaluation Results

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"Leetcode-Interview algorithm classic-java Implementation" "032-longest Valid parentheses (maximum effective bracket)"