Design an algorithm to encode a list of strings to a string. The encoded string is then sent over the network and is decoded back to the original list ...

In English, we have a concept called root, which can be followed by some other words to form another longer word - let’s call this word successor. For ...

You are playing the following Bulls and Cows game with your friend: You write down a number and ask your friend to guess what the number is. Each time ...

To some string S, we will perform some replacement operations that replace groups of letters with new ones (not necessarily the same size). Each repla ...

Given a non-empty list of words, return the k most frequent elements. Your answer should be sorted by frequency from highest to lowest. If two words h ...

We are given two arrays A and B of words. Each word is a string of lowercase letters. Now, say that word b is a subset of word a if every letter in b ...

Given a pattern and a string str, find if str follows the same pattern. Here follow means a full match, such that there is a bijection between a lette ...

Given a pattern and a string str, find if str follows the same pattern. Here follow means a full match, such that there is a bijection between a lette ...

Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, add spaces in s to construct a sentence where each word is ...

Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, determine if s can be segmented into a space-separated sequ ...