A monotonic stack is a stack that is always sorted in a monotonic way. The monotonic stack is a useful data structure for solving problems that require finding the next greater element or the next smaller element. Next Greater Element Given an array of integers, find the next greater element for each element in the array. The next greater element of an element x is the first greater element that..

A bitwise operation is an operation that operates on bits and performs bit-by-bit manipulation. The most Commonly used bitwise operations are: 1. AND : (a & b) 2. OR : (a | b) : 3. XOR : (a ^ b) : Exclusive OR 4. NOT : (~a) : Inverts all the bits 5. Left Shift : (a > b) :Mathematically, a >> b is equivalent to a / 2^b 2. Logical Right Shift : (a >>> b) :Mathematically, a >>> b is equivalent to a..

TreeMap is a sorted map implementation based on a red-black tree. The elements are sorted by their keys, which are inserted into the map using the put() method or can be specified in the constructor. The map is sorted according to the natural ordering of its keys, or by a Comparator provided at map creation time, depending on which constructor is used. So what is red-black tree? A red-black tree..

718. Maximum Length of Repeated Subarray This question helps circumvent struggles with dynamic programming questions but after few trials you would find it easier to draw tabulation that can help solve the question. Initial TLE Solution "Sets" Approach The most ubiquitous way to find a set(subarray) is using Sets from the java "maximum length of a subarray" libraries. How we generate sets can be..

Initially when you read the question.What first came to mind could be using "Two Heaps" approach. How would Two Heaps work? If the numbers and the multipliers are kept in two maximum heap and we continuously poll(remove) from the heaps we can perform multiplication operations until the heaps of numbers is multipliers is empty. public int maximumScoreTwoHeaps(int[] nums, int[] multipliers) { Prio..

The question seems to make it clear we need to check if each route from root to leaf node has any pseudo-palindromic. In my first approach I was only interested in keeping the list of each route Now check if any of this list is pseudo-palindromic. The code below makes it easy without considering the constraints of this question The number of nodes in the tree is in the range [1, 10^5]. Well this..

Leetcode Question 82 and 83 is all about working with duplicates. In this case we want to kill a bird with one stone. How we would achieve that is by first seeing how we solved the question 82 Remove Duplicates from Sorted List II Given the head of a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list. Return the linked list sort..

“Don't get too deep, it leads to over thinking, and over thinking leads to problems that doesn't even exist in the first place.” – Jayson Engay The quote defines how much human's overthink even in simple situations like "Counting Good Nodes". I get baffled to overthink in situations when my seemingly correct code does not past few cases in leetcode submission. 💭Aww well maybe we all over..

It sorts the directed graph in a linear ordering where each vertices like uv from the vertex u to vertex v,u comes before v in the ordering. Applications: School class prerequisites Task scheduling system in a distributed system. etcTopological Sorting Conditions No directed cycles in the graph At least one topological sorting for every Directed Acyclic Graph Kahn's algorithm DFS We cannot u..

The basic technique of most trees(Binary) uses the concept of DFS or BFS. The order of which we explore a three determines if its PRE_ORDER,POST_ORDER,IN_ORDER. I assume this concepts is all about doing same thing in ONLY 3 STEPS. VISIT ROOT - VISIT LEFT - VISIT RIGHT VISIT LEFT - VISIT ROOT - VISIT RIGHT VISIT RIGHT - VISIT LEFT - VISIT ROOT The order of which this visit is done determines if i..