LeetCode Find Duplicate Subtrees Given a binary tree, return all duplicate subtrees. For each kind of duplicate subtrees, you only need to return the root node of any one of them. Two trees are duplicate if they have the same structure with same node... Read More

# LeetCode Replace Words

LeetCode Replace Words 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 example, the root an, followed by other, which can form another... Read More

# LeetCode Palindromic Substrings

LeetCode Palindromic Substrings Given a string, your task is to count how many palindromic substrings in this string. The substrings with different start indexes or end indexes are counted as different substrings even they consist of same... Read More

# LeetCode Maximum Length of Pair Chain

LeetCode Maximum Length of Pair Chain You are given n pairs of numbers. In every pair, the first number is always smaller than the second number. Now, we define a pair (c, d) can follow another pair (a, b) if and only if b < c. Chain of pairs... Read More

# LeetCode Set Mismatch

LeetCode Set Mismatch 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 number in the set, which results in repetition of one number and loss of... Read More

# LeetCode Design Search Autocomplete System

LeetCode Design Search Autocomplete System Design a search autocomplete system for a search engine. Users may input a sentence (at least one word and end with a special character '#'). For each character they type except '#', you need to return... Read More

# LeetCode Exclusive Time of Functions

LeetCode Exclusive Time of Functions Given the running logs of n functions that are executed in a nonpreemptive single threaded CPU, find the exclusive time of these functions. Each function has a unique id, start from 0 to n-1. A function may be... Read More

# LeetCode Maximum Average Subarray I

LeetCode Maximum Average Subarray I Given an array consisting of n integers, find the contiguous subarray of given length k that has the maximum average value. And you need to output the maximum average value. Example 1: Input: , k = 4 Output:... Read More

# LeetCode Shopping Offers

LeetCode Shopping Offers In LeetCode Store, there are some kinds of items to sell. Each item has a price. However, there are some special offers, and a special offer consists of one or more different kinds of items with a sale price. You are given the... Read More

# LeetCode Decode Ways II

LeetCode Decode Ways II A message containing letters from A-Z is being encoded to numbers using the following mapping way: 'A' -> 1 'B' -> 2 ... 'Z' -> 26 Beyond that, now the encoded string can also contain the character '*', which can... Read More