• Tree

  22 Jun 2019

  Tree To List

  Tree Check Mirror

  Print Root Leaf Path Without Recursion

  Print All Root Leaf Paths

  Find Minimum Depth

  Find Maximum Depth

  Construct Inorder Preorder

  Check Root To Leaf Sum

  Check Bst

  Tree Check Complete

  Tree Right View

  Sum Root To Leaf Numbers

  Tree Traversal Spiral

  Tree Convert Mirror

  Tree Check Isomorphic

  Sorted Array to Balanced BST

• Stack

  22 Jun 2019

  Stack Stock Span

  Stack Next Great Element

  Stack Two Array

  Stack Longest Valid Parentheses

  Stack Check Balanced Parentheses

• Queue

  22 Jun 2019

  Queue List Implementation

  Queue Array Implementation

• Matrix

  22 Jun 2019

  Maximum Square Submatrix

  Matrix Search Sorted

  Maximum Sum Rectangle

• List

  22 Jun 2019

  List Rearrange Odd Then Even

  List Flattening

  List Delete N Nodes After M Nodes

  List Check Circular

  List Binary To Decimal

  List Add 1

  List Reverse

  List Intersection

  List Detect Loop

• Graph

  22 Jun 2019

  Graph Depth First Search

  Graph Breadth First Search

• Array

  22 Jun 2019

  Two Sum

  Template

  Binary Search Variants

  Stock Buy Sell At Most K Times

  Stock Buy Sell

  Stock Buy Sell Once

  Array Search Sorted Rotated

  Median Of Stream

  Array Sort 0 1 2

  Array Majority Element

  Smallest Sum Contiguous Subarray

  Largest Sum Contiguous Subarray

• String Longest Valid Parentheses

  19 Jun 2019

  public int longestValidParentheses(String s) {
  	int left = 0, right = 0, maxlength = 0;
  	for (int i = 0; i < s.length(); i++) {
  		if (s.charAt(i) == '(') {
  			left++;
  		} else {
  			right++;
  		}
  		if (left == right) {
  			maxlength = Math.max(maxlength, 2 * right);
  		} else if (right >= left) {
  			left = right = 0;
  		}
  	}
  	left = right = 0;
  	for (int i = s.length() - 1; i >= 0; i--) {
  		if (s.charAt(i) == '(') {
  			left++;
  		} else {
  			right++;
  		}
  		if (left == right) {
  			maxlength = Math.max(maxlength, 2 * left);
  		} else if (left >= right) {
  			left = right = 0;
  		}
  	}
  	return maxlength;
  }
  

• Dp Longest Valid Parentheses

  19 Jun 2019

  int longestValidParentheses(String s) {
  	int maxans = 0;
  	int dp[] = new int[s.length()];
  	for (int i = 1; i < s.length(); i++) {
  		if (s.charAt(i) == ')') {
  			if (s.charAt(i - 1) == '(') {
  				dp[i] = (i >= 2 ? dp[i - 2] : 0) + 2;
  			} else if (i - dp[i - 1] > 0 && s.charAt(i - dp[i - 1] - 1) == '(') {
  				dp[i] = dp[i - 1] + ((i - dp[i - 1]) >= 2 ? dp[i - dp[i - 1] - 2] : 0) + 2;
  			}
  			maxans = Math.max(maxans, dp[i]);
  		}
  	}
  	return maxans;
  }
  

• Zigzag Tree Traversal

  16 Jun 2019

  ```java void printZigZagTraversal() {