Smallest Number after Removing K digits
Objective: Given a number with N digits, write a program to get the smallest number possible after removing k digits from number N. OR Implement a method that returns the lowest possible number that...
Category: Expert
Reverse a Stack using recursion – In Place (Without using extra memory)
Objective: Given a Stack, write an algorithm to reverse the stack. Example: Original Stack: [14, 9, 67, 91, 101, 25] Reversed Stack: [25, 101, 91, 67, 9, 14] Approach: Use Recursion In this solution,...
K-Means Algorithm
The algorithm of kMeans is an unsupervised learning algorithm for clustering a set of items into groups. Given a set of multi-dimensional items and a number of clusters, k, we are tasked of categorizing...
Least Recently Used (LRU) Cache – Using LinkedHashSet and Deque | Set 2
Objective: Design and Implement a data structure Least Recently Used (LRU) Cache. Earlier we had seen Least Recently Used (LRU) Cache – Using HashMap and Doubly Linked List. In this article, we will see...
Least Recently Used (LRU) Cache – Using HashMap and Doubly Linked List | Set 1
Objective: Design and Implement a data structure Least Recently Used (LRU) Cache. Least Recently Used (LRU) Cache: You have given a cache (or memory) capacity. The cache will be filled with items you will...
Find the nearest building which has bike | Find nearest specific vertex from source in a graph.
Objective: Given a matrix (NxN) which represents the buildings in community. You are in a building and you need a bike to travel. There are few buildings in community which has bikes which you...
Max Flow Problem – Introduction
Max Flow Problem- Maximum flow problems find a feasible flow through a single-source, single-sink flow network that is maximum. This problem is useful for solving complex network flow problems such as the circulation problem. The maximum value...
Dijkstra Algorithm Implementation – TreeSet and Pair Class
Earlier we have seen what Dijkstra algorithm is is and how it works. In this article we will see its implementation using adjacency list and TreeSet. Example: Implementation – Adjacency List and Priority Queue...
Find no of reverse pairs in an array which is sorted in two parts in O(N)
Objective: Given an array of integers A[] which is sorted in two parts (both parts are individually sorted), find no of reverse pairs means no of (i, j) pairs where i belongs to the...
Dijkstra’s – Shortest Path Algorithm (SPT) – Adjacency List and Priority Queue – Java Implementation
Earlier we have seen what Dijkstra’s algorithm is and how it works. In this article we will see its implementation using adjacency list and Priority Queue. Prerequisites: Adjacency List Priority Queue Dijkstra’s Algorithm basics...
Dijkstra’s – Shortest Path Algorithm (SPT) – Adjacency List and Min Heap – Java Implementation
Earlier we have seen the basics of Dijkstra algorithm. In this article we will see its implementation using adjacency list and Min Heap. We strongly recommend reading the following articles Dijkstra algorithm and how...
Dijkstra’s – Shortest Path Algorithm (SPT) – Adjacency Matrix – Java Implementation
Earlier we have seen what Dijkstra’s algorithm is and how it works. In this article we will see its implementation using adjacency matrix. We strongly recommend reading – Dijkstra algorithm and how it works....
Djkstra’s – Shortest Path Algorithm (SPT)
What is Dijkstra’s algorithm? Dijkstra algorithm is a greedy algorithm. It finds a shortest path tree for a weighted undirected graph. This means it finds a shortest paths between nodes in a graph, which may represent, for example, road networks For a given...
Kruskal’s Algorithm – Minimum Spanning Tree (MST) – Complete Java Implementation
What is Kruskal Algorithm? Kruskal’s algorithm for finding the Minimum Spanning Tree(MST), which finds an edge of the least possible weight that connects any two trees in the forest It is a greedy algorithm. It...
Prim’s – Minimum Spanning Tree (MST) |using Adjacency List and Priority Queue without decrease key in O(ElogV)
Earlier we have seen the implementation of prim’s algorithm using priority queue with decrease key and how decrease key has increased the time complexity. In this article we will improve the implementation(without decrease key)...