Suppose we have a string containing only 4 kinds of characters 'Q', 'W', 'E' and 'R'. A string will be balanced if each of its characters appears n/4 times where n is the length of the string. Find the minimum length of the substring that can be replaced with any ... Read More

Suppose we have an array of strings products and a string called searchWord. We want to design a module that suggests at most three product names from products list after each character of searchWord is typed. The suggested products should have common prefix with the searchWord. When there are more ... Read More

Suppose we have a binary tree. The rules of that tree is as follows −root.val == 0If treeNode.val is x and treeNode.left is not null, then treeNode.left.val = 2 * x + 1If treeNode.val is x and treeNode.right is not null, then treeNode.right.val = 2 * x + 2Now as ... Read More

Suppose we have a string s of '(' , ')' and lowercase English characters. We have to remove the minimum number of parentheses ( '(' or ')', in any positions ) so that the resulting parenthese string is valid and return any valid string. A parentheses string is valid when ... Read More

Suppose we have a 2D grid consists of 0s (as land) and 1s (as water). An island is a maximal 4- directionally connected group of 0s. A closed island is an island totally surrounded by 1s. We have to find the number of closed islands. So if the grid is ... Read More

Suppose we have a string, that string is a valid parentheses string (denoted VPS) if and only if it consists of "(" and ")" characters only, and it satisfies these properties −It is the empty string, orIt can be written as AB, where A and B are VPS's, orIt can ... Read More

Suppose we have an N by N square grid, there each cell is either empty (0) or blocked (1). A clear path from top-left to bottom-right has length k if and only if it is composed of cells C_1, C_2, ..., C_k such that −Adjacent cells C_i and C_{i+1} are ... Read More

Suppose a bookstore owner has a store open for number of customers list entries minutes. In every minute, some number of customers (customers[i]) enter the store, after that all those customers leave after the end of that minute. On some minutes, the owner is grumpy. Now if the owner is ... Read More

Suppose we have the root of a binary tree, we have to find the maximum value V for which there exists different nodes A and B where V = |value of A – value of B| and A is an ancestor of B. So if the tree is like −Then ... Read More

Suppose there is a conveyor belt has packages that will be shipped from one port to another within D days. Here the i-th package on the conveyor belt has a weight of weights[i]. Each day, we will load the ship with packages on the belt. We will not load more ... Read More