539. Minimum Time Difference
Given a list of 24-hour clock time points in “HH:MM” format, return the minimum minutes difference between any two time-points in the list. Example 1: […]
Longest Valid Parentheses
Given a string str consisting of opening and closing parenthesis ‘(‘ and ‘)‘. Find length of the longest valid parenthesis substring. A
1371. Find the Longest Substring Containing Vowels in Even Counts
Given the string s, return the size of the longest substring containing each vowel an even number of times. That is,
Binary Tree to DLL
Given a Binary Tree (BT), convert it to a Doubly Linked List (DLL) in place. The left and right pointers
2419. Longest Subarray With Maximum Bitwise AND
You are given an integer array nums of size n. Consider a non-empty subarray from nums that has the maximum possible bitwise AND. In other words, let k be the maximum value
Alternate Positive And Negative Numbers
Given an unsorted array arr containingbothpositive and negative numbers. Your task is to create an array of alternate positive and negative numbers without changing the
1310. XOR Queries of a Subarray
You are given an array arr of positive integers. You are also given the array queries where queries[i] = [lefti, righti]. For each query i compute the XOR of
Mirror Tree
Given a Binary Tree, convert it into its mirror. Examples: Input: 1 / \ 2 3 Output: 3
1684. Count the Number of Consistent Strings
You are given a string allowed consisting of distinct characters and an array of strings words. A string is consistent if all characters in the string appear
Middle of a Linked List
Given the head of a linked list, the task is to find the middle. For example, the middle of 1-> 2->3->4->5 is 3. If
2220. Minimum Bit Flips to Convert Number
A bit flip of a number x is choosing a bit in the binary representation of x and flipping it from either 0 to 1 or 1 to 0. For example, for x = 7, the
Minimum Cost Of Ropes
Given an array arr containing the lengths of the different ropes, we need to connect these ropes to form one rope. The cost to