Find the minimum length word from a given dictionary words, which has all the letters from the string licensePlate. Such a word is said to complete th ...

We are given two strings, A and B. A shift on A consists of taking string A and moving the leftmost character to the rightmost position. For example, ...

X is a good number if after rotating each digit individually by 180 degrees, we get a valid number that is different from X. Each digit must be rotat ...

Given a non-empty array of non-negative integers nums, the degree of this array is defined as the maximum frequency of any one of its elements. Your t ...

Given a positive integer, check whether it has alternating bits: namely, if two adjacent bits will always have different values. ExampleNo.1Input: 5 O ...

Given an array with n integers, your task is to check if it could become non-decreasing by modifying at most 1 element. We define an array is non-decr ...

Design a max stack that supports push, pop, top, peekMax and popMax. push(x) – Push element x onto stack. pop() – Remove the element on top of the st ...

Given two strings A and B, find the minimum number of times A has to be repeated such that B is a substring of it. If no such solution, return -1. For ...

Given a 2D integer matrix M representing the gray scale of an image, you need to design a smoother to make the gray scale of each cell becomes the ave ...

The set S originally contains numbers from 1 to n. But unfortunately, due to the data error, one of the numbers in the set got duplicated to another n ...