Implement a queue using the stack data structure
This post will implement a queue using the stack data structure. In other words, design a queue that supports enqueue and dequeue operations using standard push and pop operations of the stack.
Tag: Recursive
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.
Find all n-digit numbers with equal sum of digits at even and odd indices
Find all n–digit numbers with an equal sum of digits at even and odd index, where n varies from 1 to 9.
Find total ways to achieve a given sum with `n` throws of dice having `k` faces
Calculate the total number of ways to achieve a given sum with n throws of dice having k faces.
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 inorder successor for the given key in a BST
Given a BST, find the inorder successor of a given key in it. If the given key does not lie in the BST, then return the next greater key (if any) present in the BST.
Find the maximum sum path between two leaves in a binary tree
Given a binary tree, write an efficient algorithm to find the maximum sum path between any two leaves in it.
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.
Print all combinations of numbers from 1 to `n` having sum `n`
Given a positive integer n, print all combinations of numbers between 1 and n having sum n.
Print binary representation of a number – C, C++, Java, and Python
Print binary representation of a given number in C, C++, Java, and Python using built-in methods and custom routines.