Suppose we have n cities connected by m flights. Each flight starts from u and arrives at v with a price w. If we have all the cities and flights, together with starting city src and the destination dst, here our task is to find the cheapest price from src to dst with up to k stops. If there is no such route, then return -1.So, if the input is like n = 3, edges = [[0, 1, 100], [1, 2, 100], [0, 2, 500]], src = 0, dst = 2, k = 1, then the output will be 200To ... Read More

Suppose we have one unrooted tree; this is one undirected graph with no cycles. The given input is a graph that started as a tree with N nodes (values of the nodes are distinct values ranging from 1 through N), with one additional edge added. The added edge has two different vertices chosen from 1 to N, and was not an edge that already existed.The final graph is given as a 2D-array of edges. Each element of edges is a pair [u, v] where u < v, that represents an undirected edge connecting nodes u and v.We have to find ... Read More

Suppose we have a binary tree, we also have the value v and depth d, we have to add a row of nodes with value v at the given depth d. The root node is at depth 1. We have to follow this rule to perform this operation −As we know the depth d, for each valid tree nodes N in depth d-1, we have to create two tree nodes with value v as N's left subtree root and right subtree root. And N's original left subtree will be the left subtree of the new left subtree root, its original ... Read More

Suppose we have a string containing only digits, we have to restore it by returning all possible valid IP address combinations. We know that a valid IP address consists of exactly four integers (each integer is in range 0 to 255) separated by single points.So, if the input is like "25525511135", then the output will be ["255.255.11.135", "255.255.111.35"]To solve this, we will follow these steps −Define a function convertToNum(), this will take s, start, end, num := 0for initialize i := start, when i 255, then −return 10000return numDefine a function addDots(), this will take positions, res := blank ... Read More

Suppose we have a binary tree where each path going from the root to any leaf form a valid sequence, we have to check whether a given string is a valid sequence in such binary tree or not.We will get the given string from the concatenation of an array of integers arr and the concatenation of all values of the nodes along a path results in a sequenceSuppose we have a binary tree like.So, if arr = [0, 1, 0, 1], then the output will be True, as the path 0 -> 1 -> 0 -> 1 is a valid ... Read More

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