My code: public class Solution { public String toHex(int num) { if (num == 0) { return "0"; } String[] strs = …

Given a string S and a string T, count the number of distinct subsequences of S which equals T. A subsequence …

Problem Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring…

35. Search Insert Position 题目 Given a sorted array and a target value, return the index if the target is found…

  We are playing the Guess Game. The game is as follows:   I pick a number from 1 to …

  Initially on a notepad only one character ‘A’ is present. You can perform two operations on…

这是悦乐书的第167次更新，第169篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第26题（顺位题号是110）。给定二叉树，判断它是否是高度平衡的。对于此问题，高度平衡二叉树定义为：一个二叉…

class Solution(object): def minDistance(self, s1, s2): """ :type word1: str :type word2: str :rtype: int """ #…

题目 Write a function that takes a string as input and returns the string reversed. Example: Given s = “he…

  Given a collection of integers that might contain duplicates, S, return all possible subsets. Note…

  Suppose you have a random list of people standing in a queue. Each person is described by a pair of int…

  Given a chemical formula (given as a string), return the count of each atom. An atomic elemen…