Ace your Coding Interview
Get hired by top tech companies with our comprehensive interview preparation.
Get StartedGiven 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).
Given a string and a pattern containing wildcard characters, write an efficient algorithm to check if the string matches with the wildcard pattern or not.
There are two players, A & B, in the Pots of the gold game, and pots of gold arranged in a line, each containing some gold coins. The players can see how many coins are there in each gold pot, and each player gets alternating turns in which the player can pick a pot from one of the ends of the line.
This post will discuss how to reverse an array in C++.
Given a binary tree, write an efficient algorithm to print its right view. For example, the right view of a given binary tree is 1, 3, 6, 8.
Given a binary tree whose nodes are labeled from 0 to N-1, construct an N × N ancestor matrix. An ancestor matrix is a boolean matrix, whose cell (i, j) is true if i is an ancestor of j in the binary tree.
Given a sorted doubly linked list, in-place convert it into a height-balanced Binary Search Tree (BST). The difference between the height of the left and right subtree for every node of a height-balanced BST is never greater than 1.
Given a map containing employee to manager mappings, find all employees under each manager who directly or indirectly reports him.
Write an efficient algorithm to find postorder traversal on a given binary tree from its inorder and preorder sequence.
Given a BST and a valid range of keys, remove nodes from BST that have keys outside the valid range.
This post will discuss how to reverse a string using the stack data structure in C/C++, Java, and Python using explicit stack and call stack.
In this post, we will see how to find all lexicographic permutations of a string where the repetition of characters is allowed.