Efficiently print all nodes between two given levels in a binary tree
Given a binary tree, efficiently print all nodes between two given levels in a binary tree. The nodes for any level should be printed from left to right.
Tag: Depth-first search
Find the path between given vertices in a directed graph
Given a directed graph and two vertices (say source and destination vertex), determine if the destination vertex is reachable from the source vertex or not. If a path exists from the source vertex to the destination vertex, print it.
Print nodes of a binary tree in vertical order
Given a binary tree, print its nodes in vertical order. Assume that the left and right child of a node makes a 45–degree angle with the parent.
Link nodes present in each level of a binary tree in the form of a linked list
Given a binary tree, write an efficient algorithm to link nodes at the same level in the form of a linked list like structure.
Find preorder traversal of a binary tree from its inorder and postorder sequence
Write an efficient algorithm to find a binary tree’s preorder traversal from its inorder and postorder sequence without constructing the tree.
Count all subtrees having the same value of nodes in a binary tree
Given a binary tree, count all subtrees in it such that every node in the subtree has the same value.
Find all nodes at a given distance from leaf nodes in a binary tree
Given a binary tree, write an efficient algorithm to find all nodes present at a given distance from any leaf node. We need to find only those nodes that are present in the root-to-leaf path for that leaf.
Fix a binary tree that is only one swap away from becoming a BST
Given a binary tree that is only one swap away from becoming a BST, convert it into a BST in a single traversal.
Update every key in a BST to contain the sum of all greater keys
Given a binary search tree, modify it such that every key is updated to contain the sum of all greater keys present in the BST.
Find the maximum difference between a node and its descendants in a binary tree
Given a binary tree, find the maximum difference between a node and its descendants in it.
Find the length of the longest path in a matrix with consecutive characters
Given an M × N matrix of characters, find the length of the longest path in the matrix starting from a given character. All characters in the longest path should be increasing and consecutive to each other in alphabetical order.
Replace all occurrences of 0 that are surrounded by 1 in a binary matrix
Given an M × N binary matrix, replace all occurrences of 0’s by 1’s, which are completely surrounded by 1’s from all sides (top, left, bottom, right, top-left, top-right, bottom-left, and bottom-right).