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Get StartedGiven a string sorted in descending order, find all lexicographically previous permutations of it. In the lexicographic order, the words are arranged similarly as they are presumed to appear in a dictionary.
Write an efficient algorithm to construct a binary tree from the given inorder and preorder sequence.
Given a binary search tree, find a triplet with a given sum present in it.
Given two binary search trees, merge them into a doubly-linked list in sorted order.
Given a directed acyclic graph (DAG) and a source vertex, find the cost of the longest path from the source vertex to all other vertices present in the graph. If the vertex can’t be reached from the given source vertex, print its distance as infinity.
Given a binary search tree (BST), convert it into a height-balanced binary search tree. For a height-balanced binary search tree, the difference between the height of the left and right subtree of every node is never more than 1.
Given a binary tree, find the size of the largest BST (Binary Search Tree) in it.
Given a Directed Acyclic Graph (DAG), print all its topological orderings. A Topological ordering of a directed graph G is a linear ordering of the nodes as v1, v2,…,vn such that all edges point forward: for every edge (vi, vj), we have i < j.
Write an efficient algorithm to construct a full binary tree from a sequence of keys representing preorder traversal and a boolean array that determines if the corresponding key in the preorder traversal is a leaf node or an internal node.
Given a distinct sequence of keys, check if it can represent a preorder traversal of a binary search tree (BST).
A full binary tree is a tree in which every node has either 0 or 2 children. Write an efficient algorithm to construct a full binary tree from a given preorder and postorder sequence.
Given a stack, recursively reverse it only using its abstract data type (ADT) standard operations, i.e., push(item), pop(), peek(), isEmpty(), size(), etc.