天天向上

一、问题描述 The string “PAYPALISHIRING” is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) And then read li...

一、问题描述 Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123 Output: 321 Example 2: Input: -123 Output: -321 Example 3: Input: 120 Output: 21 Note: Assume we ...

一、题目描述 Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible in...

一、题目描述 Determine whether an integer is a palindrome. Do this without extra space. Some hints: Could negative integers be palindromes? (ie, -1) If you are thinking of converting the integer to stri...

一、题目说明： Given a string, find the length of the longest substring without repeating characters. Examples: Given “abcabcbb”, the answer is “abc”, which the length is 3. Given “bbbbb”, the answer is ...

一、题目描述 There are two sorted arrays nums1 and nums2 of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)). Example 1: nums1 ...

一、问题描述 Given a string s, find the longest palindromic substring *（最长回文字符串）*in s. You may assume that the maximum length of s is 1000. Example: Input: “babad” Output: “bab” Note: “aba” is also a v...

一、问题描述 Given a string s, find the longest palindromic substring（最长回文字符串） in s. You may assume that the maximum length of s is 1000. Example: Input: “babad” Output: “bab” Note: “aba” is also a val...

一、问题描述 Given a string s, find the longest palindromic substring（最长回文字符串） in s. You may assume that the maximum length of s is 1000. Example: Input: “babad” Output: “bab” Note: “aba” is also a val...