A substring is a sequence of characters which has been extracted from a larger string. For example, let’s consider the string “Hello World”. We can form the substring “Hello” by selecting the first five characters of the string. Let’s see the following another example. In order to calculate the length of a substring, we needRead More »
We are aiming to find the total number of subsets with a given sum in an array of unsorted integers of size ‘N.’ For example, given an array {1, 2, 3, 4} and a sum of 6, the subsets with sum 6 are {1, 2, 3} and {2, 4}, making the count of subsets 2.Read More »
Topological sorting forms with the ordering of all its vertices topologically. A topological ordering of any edge “U–>V” in an acyclic directed graph starts with “U” then “V”. For example we can think of any processes dependency in which task ‘U’ needs to finish first to execute process ‘V’. We cannot do topological sorting onRead More »
Edit distance The minimum number of operations on a string (array of characters) to convert into another input string is called the edit distance between the two strings. The operations can be Insert a character, Remove a character, or Replace a character with another. We can solve this problem using recursion. Now let’s take aRead More »
Given an input of ‘N’ unsorted integers in which we need to find the given K-th largest or smallest integer. This is one of the most commonly asked interview questions asking in recent days. As there are multiple ways to solve this problem, in this article I am discussing two optimized solutions for this problem.Read More »
Given an array of unsorted integers with both negative and positive values. We aim to find a subarray in which the sum of all integers is maximum than any other subarray of the given array. Let’s understand this with the below example image. The above input array has integers of size 7 and its maximumRead More »
An unsorted integer stream is coming, we need to always keep the median of all the stream elements. The median can be defined as follows. To find the median of any given array, Sort the array Find integer(s) in the middle of the sorted array The average of middle these integers is median ( IfRead More »
Consider we have a singly linked list of “N” nodes, in which we aim to reverse alternate “K” nodes. Let’s see the below pictorial representation of a singly linked list. Here, our input linked list of size 7 nodes is 10->20->30->40->50->60->70->NULL and we want to reverse every alternative 3 (K) nodes group, pictorial representation ofRead More »
Given a binary tree with all positive integer nodes, we need to find the path from the root to a leaf whose sum is maximum in all root to leaf paths of the binary tree. The above diagram shows a simple binary tree with the maximum sum path [24, 16, 12]. This algorithm needs anRead More »
A vertical order traversal is one of the binary tree traversals, where all elements are vertically at the same level, displays as an array of elements. If someone looks at a 3D model of the binary tree from bottom to top way, all the rear nodes which are hidden by front nodes, come under theRead More »
Given a binary tree with integer nodes in it, the aim is to find verticals sum. Let’s discuss this with the below example. As shown in the image above, each vertical level has an index, like {-2, -1, 0, 1, 2} in the above picture. The result should be the sum of all the nodesRead More »
Given a binary tree and two integer nodes on it, the aim is to find the lowest common ancestor of the nodes in a given binary tree. A lowest common ancestor is the lowest common parent node of the respective nodes. Let’s check this with a couple of examples. We can solve this problem recursively,Read More »
Given a binary tree, we aim to find its mirror tree. A Mirror tree is a binary tree where it’s left and right subtrees are swaps its positions. A recursive definition of the mirror tree is a binary tree T(P, L, R) is T(P, T(R), T(L)). Here both L(left) and R(right) subtrees swapped their positionRead More »
The diameter of a binary tree is the longest distance between two leaf nodes. These leaf nodes are nodes from the root node or leaf nodes of any subtrees’ of the binary tree. Let’s see below two example binary trees diameter At any specific node it calculates as the sum of heights of left childRead More »
A binary tree with integer nodes is given, we aim to convert this binary tree to its sum tree in-place. A Sum Tree is a binary tree in which the value of the current node is a sum of data of all its descendent nodes data. Let’s see below the binary tree and its sumRead More »