Isomorphic Strings – Given two strings we need to check if for every occurrence of a character in string1 there is a unique mapping with characters in string2. In short, check, if there is one to one mapping or not. Example Input str1 = “aab” str2 = “xxy” Output True …
Problem Statement The problem “Climbing stairs” states that you are given a staircase with n stairs. At a time you can either climb one stair or two stairs. How many numbers of ways to reach the top of the staircase? Example 3 3 Explanation There are three ways to climb …
Given a directed acyclic graph, topologically sort the graph nodes. Topological Sorting Example Topological sorting of above graph is -> {1,2,3,0,5,4} Theory Topological Sorting is done for a Directed Acyclic Graph (DAG). A DAG has no cycles in it. ie, there is no such path starting from any node of …
A shift is a process in which alphabets are incremented by 1 in their ASCII value. For the last alphabet z it starts again i.e. shift of z will be a. In perform string shifts leetcode problem we have Given a string s (lowercase characters only) and an array a[ …
Breadth First Search (BFS) Do we already know about what actually BFS is? if not then don’t need to feel bad just read the whole article and visit our previous article on Breadth First Search for better understanding. BFS is a level order traversal in which we visit the nodes of …
Breadth First Search (BFS) for a graph is a traversing or searching algorithm in tree/graph data structure. It starts at a given vertex(any arbitrary vertex) and explores all the connected vertex and after that moves to the nearest vertex and explores all the unexplored nodes and takes care that no …
In String comparison containing wildcards problem, we have given two strings second string contains small alphabets and the first contains small alphabets and some wildcard patterns. Wildcard patterns are: ?: we can replace this wildcard with any small alphabet. *: we can replace this wildcard with any string. An empty …
We have given a binary tree containing N number of nodes where each node has some value. We need to serialize and deserialize the binary tree. Serialize The process of storing a tree in a file without disturbing its structure is called serialization. DeserializeSerialize and Deserialize Binary Tree The process …
Problem Statement The problem “reverse a linked list” states that we are given the head of the linked list. We have to reverse the linked list by changing the links between them and return the head of the reversed linked list. Example 10->20->30->40->NULL NULL<-10<-20<-30<-40 Explanation We have reversed the linked …
In the subset sum problem, we are given a list of all positive numbers and a Sum. We need to check if there is a subset whose sum is equal to the given sum. Example Input List of numbers: 1 2 3 10 5 sum: 9 Output true Explanation for …