Suppose there are three integer arrays arr1, arr2 and arr3 and they are sorted in strictly increasing order, we have to return a sorted array of only the integers that appeared in all of these three arrays. So if arrays are [1, 2, 3, 4, 5], [1, 2, 5, 7, 9], and [1, 3, 4, 5, 8], so the output will be [1, 5]To solve this, we will follow these steps −define an array called rescreate three maps f1, f2 and f3for i in range 0 to length of arr1f1[arr1[i]] increase by 1for i in range 0 to length of ... Read More

Suppose we have an integer array with all positive numbers and all elements are unique, find the number of possible combinations, so that if we add up, we will get positive integer target.So if the array is [1, 2, 3] and the target is 4, then the possible combinations will be [[1, 1, 1, 1], [1, 1, 2], [1, 2, 1], [2, 1, 1], [1, 3], [3, 1], [2, 2]], so output will be 7.To solve this, we will follow these steps −Suppose we have one recursive function called solve(), this is taking array, target and another array for dynamic ... Read More

Suppose we have coins of different denominations and a total amount of money amount. We have to define one function to compute the fewest number of coins that we need to make up that amount. When that amount of money cannot be accommodated by any combination of the coins, return -1. So if the input is [1, 2, 5], and the amount is 11, the output is 3. This is formed using 5 + 5 + 1 = 11.To solve this, we will follow these steps −if amount = 0, then return 0if minimum of coins array > amount, then ... Read More

Suppose we have a binary tree containing digits from 0-9 only, here all root-to-leaf path could represent a number.So if the tree is like −This is representing two paths 21 and 23, so the output will be 21 + 23 = 44.To solve this, we will follow these steps −Create one recursive function called dfs(), this will take root, and num. initially num = 0if the node is not nullnum := num * 10 + value of nodeif node right is not null and node left is not null, then’sum := sum + numnum := num / 10return from the ... Read More

A binary search tree is a special binary tree in which for every node, the left subtree contains values less than the node's value, and the right subtree contains values greater than the node's value. In this article, we will discuss how to validate whether a given binary tree is a valid binary search tree (BST) in Python. Validate Binary Search Tree Algorithm to Validate Binary Search Tree Python Program to Validate Binary Search Tree Validate Binary Search Tree Given a root node of ... Read More

The Unique Binary Search Trees problem is a classic dynamic programming problem that counts the number of unique binary search tree (BSTs) that can be formed with a given number of nodes. In this article, we will explain the problem, testcases, its solution, and provide a C++ implementation. Number of Unique BSTs In this problem, we are given an integer n, which represents the number of nodes in a binary search tree. The task is to find the number of different BSTs that can be formed using these n nodes and return the count. To understand the problem better, ... Read More

Suppose we have an integer n, we have to generate all structurally unique binary search trees that store values from 1 to n. So if the input is 3, then the trees will be −To solve this, we will follow these steps −Define one recursive function called generate(), this will take low and highdefine one tree node called temp.if low > high, then insert null into the temp, and return tempfor i in range low to highleft_subtree := generate(low, i – 1)right_subtree := generate(i + 1, high)current := ifor j in range 0 to size of the left_subtreefor k in ... Read More

Given is the task to show the functionality of Deque insert( ) function in C++ STLWhat is Deque?Deque is the Double Ended Queues that are the sequence containers which provides the functionality of expansion and contraction on both the ends. A queue data structure allow user to insert data only at the END and delete data from the FRONT. Let’s take the analogy of queues at bus stops where the person can be inserted to a queue from the END only and the person standing in the FRONT is the first to be removed whereas in Double ended queue the ... Read More

In this article we will be discussing the working, syntax and examples of list::clear() function in C++.What is a List in STL?List is a data structure that allows constant time insertion and deletion anywhere in sequence. Lists are implemented as doubly linked lists. Lists allow non-contiguous memory allocation. List perform better insertion extraction and moving of element in any position in container than array, vector and deque. In List the direct access to the element is slow and list is similar to forward_list, but forward list objects are single linked lists and they can only be iterated forwards.What is clea()?list::clear() ... Read More

In this article we will be discussing the working, syntax and examples of remove() function in C++.What is a List in STLList is a data structure that allows constant time insertion and deletion anywhere in sequence. Lists are implemented as doubly linked lists. Lists allow non-contiguous memory allocation. List perform better insertion extraction and moving of element in any position in container than array, vector and deque. In List the direct access to the element is slow and list is similar to forward_list, but forward list objects are single linked lists and they can only be iterated forwards.What is remove()remove() ... Read More