热带雨林

摘要： Given an integer n. Each number from 1 to n is grouped according to the sum of its digits. Return how many groups have the largest size. Example 1: In 阅读全文

摘要： Implement the class UndergroundSystem that supports three methods: 1. checkIn(int id, string stationName, int t) A customer with id card equal to id, 阅读全文

摘要： There are n soldiers standing in a line. Each soldier is assigned a unique rating value. You have to form a team of 3 soldiers amongst them under the 阅读全文

摘要： Given an array of integers arr, a lucky integer is an integer which has a frequency in the array equal to its value. Return a lucky integer in the arr 阅读全文

摘要： Given two binary trees original and cloned and given a reference to a node target in the original tree. The cloned tree is a copy of the original tree 阅读全文

摘要： Given two arrays of integers nums and index. Your task is to create target array under the following rules: Initially target array is empty. From left 阅读全文

摘要： Given two integer arrays arr1 and arr2, and the integer d, return the distance value between the two arrays. The distance value is defined as the numb 阅读全文

摘要： Given a binary search tree, return a balanced binary search tree with the same node values. A binary search tree is balanced if and only if the depth 阅读全文

摘要： Design a stack which supports the following operations. Implement the CustomStack class: CustomStack(int maxSize) Initializes the object with maxSize  阅读全文

摘要： Given a m * n matrix of distinct numbers, return all lucky numbers in the matrix in any order. A lucky number is an element of the matrix such that it 阅读全文