Suppose we have a queue of integers, we need to retrieve the first unique integer in that queue. We have to implement the class called FirstUnique: It will be initialized by the numbers in the queue. Define one function showFirstUnique(), this will return the value of the first unique integer of the queue and returns -1 if there is no such integer. Another method is add(value) this will insert value to the queue.So, if the input is likeInitialize with [2, 3, 4] then call the functions as follows −showFirstUnique()add(5)showFirstUnique()add(2)showFirstUnique()add(3)showFirstUnique(), then the output will be 2, 2, 3, -1 respectively.To solve ... Read More

Suppose we have Given two arrays words1, words2 these are considered as sentences, and a list of similar word pairs, we have to check whether two sentences are similar or not. So if the input is like words1 = ["great", "acting", "skills"] and words2 = ["fine", "drama", "talent"] these two are similar, if the similar word pairs are like = [["great", "good"], ["fine", "good"], ["acting", "drama"], ["skills", "talent"]].The similarity relation is transitive. For example, if "great" and "good" are similar, and "fine" and "good" are similar, then "great" and "fine" are also similar. And the similarity is also symmetric. So, ... Read More

Suppose we have a node from a Circular Linked List which is sorted in increasing order, we have to define a function to insert a value insertVal into the list such that it remains a sorted circular list.The node can be a reference to any single node in the list, and may not be necessarily the first value of the circular list. If there are multiple suitable places for insertion, we can choose any place to insert the new value. If the list is empty, then we have to create a new single circular list and return the reference to ... Read More

Suppose we have an array and that is sorted in ascending order, we have to define a function to search target in nums. If the target is present, then return its index, otherwise, return -1.The array size is not known. We can only access the array using an ArrayReader interface. There is a get function like ArrayReader.get(k) this will return the element of the array at index k.So, if the input is like array = [-1, 0, 3, 5, 9, 12], target = 9, then the output will be 4 as 9 exists in nums and its index is 4To ... Read More

Suppose we have a binary 2D array grid, here an island is a group of 1's (land) connected 4- directionally (horizontal or vertical.) We can assume all four edges of the grid are surrounded by water. We have to count the number of distinct islands.An island is considered to be the same as another when one island can be translated (and not rotated or reflected) to equal the other.So, if the input is like11011100000000111011then the output will be 3To solve this, we will follow these steps −Define a function dfs(), this will take x, y, grid, temp, c, if x ... Read More

Suppose we have a time represented in the format "HH: MM", we have to generate the next closest time by reusing the current digits. We can use the digit an unlimited number of times.So, if the input is like "19:34", then the output will be "19:39" as the next closest time choosing from digits 1, 9, 3, 4, is 19:39. It is not 19:33, because this occurs 23 hours and 59 minutes later.To solve this, we will follow these steps −Define a function eval(), this will take x, a := convert x[0] to stringa := a + x[1]b := convert ... Read More

Suppose we have a list of integers that is representing a binary tree with a depth smaller than 5. If the depth of a tree is less than 5, then this tree can be represented by a list of three-digit integers. For each integer in this list −The hundreds digit is representing the depth D of this node, 1

Suppose we have a binary tree with n nodes, our task is to check whether it's possible to partition the tree to two trees which have the equal sum of values after deleting exactly one edge on the original tree.So, if the input is likethen the output will be true.To solve this, we will follow these steps −Define one stack stDefine a function solve(), this will take node, if node is null, then −return 0leftSum := solve(left of node)rightSum := solve(right of node)curr := val + leftSum + rightSum of nodeinsert curr into streturn currFrom the main method do the ... Read More

Suppose we will try to write the letter ‘A’, using the keyboard. Our goal is to use only four keys and try to write maximum ‘A’s on the text field. The keys are ‘A’, ‘C’, ‘V’, and ‘Ctrl’.To write a maximum number of A, we will use Ctrl + A to select All, Ctrl + C to copy, and Ctrl + V to paste.So, if the input is like the number of keystrokes is 7 then the output will be 9 as of press A three times.Then Ctrl+A, Ctrl+C, Ctrl+V, Ctrl+VTo solve this, we will follow these steps −if keyStrokes ... Read More

Suppose we have an array consisting of n numbers from 1 to n in increasing order, we have to find the number of derangements it can generate.We know that in combinatorial mathematics, a derangement is a permutation of the elements of a set, such that no element will appear in its original position. The answer may be very large, so return the output mod 10^9 + 7.So, if the input is like 3, then the output will be 2, as the original array is [1, 2, 3]. The two derangements are [2, 3, 1] and [3, 1, 2].To solve this, ... Read More