摘要： Given a digit string, return all possible letter combinations that the number could represent.A mapping of digit to letters (just like on the telephon... 阅读全文

摘要： Given an array ofnpositive integers and a positive integers, find the minimal length of a subarray of which the sum ≥s. If there isn't one, return 0 i... 阅读全文

摘要： Givennnon-negative integersa1,a2, ...,an, where each represents a point at coordinate (i,ai).nvertical lines are drawn such that the two endpoints of ... 阅读全文

摘要： Implementatoito convert a string to an integer.Hint:Carefully consider all possible input cases. If you want a challenge, please do not see below and ... 阅读全文

摘要： Determine whether an integer is a palindrome. Do this without extra space.类似于reverse integer。public class Solution { public boolean isPalindrome(... 阅读全文

摘要： Reverse digits of an integer.Example1:x = 123, return 321Example2:x = -123, return -321注意溢出，溢出返回0public class Solution { public int reverse(int x... 阅读全文

摘要： Given a stringS, find the longest palindromic substring inS. You may assume that the maximum length ofSis 1000, and there exists one unique longest pa... 阅读全文

摘要： Given an unsorted array of integers, find the length of the longest consecutive elements sequence.For example,Given[100, 4, 200, 1, 3, 2],The longest ... 阅读全文

摘要： You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single ... 阅读全文

摘要： Given two stringssandt, determine if they are isomorphic.Two strings are isomorphic if the characters inscan be replaced to gett.All occurrences of a ... 阅读全文