Hash Table

3. Longest Substring Without Repeating Characters题目Given a string, find the length of the longest substring without repeating characters. Example 1: 123Input: "abcabcbb"Output: 3 Explanation: The answer is "abc", with the length of 3. Example 2: 123Input: "bbbbb"Output: 1Explanation: The answer is "b", with the length of 1. Example 3: 1234Input: "pwwkew"Output: 3Explanation: The answer is "wke", with the length of 3. ...

1. Two Sum题目Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice. Example: 1234Given nums = [2, 7, 11, 15], target = 9,Because nums[0] + nums[1] = 2 + 7 = 9,return [0, 1]. 题目大意在数组中找到两个数，它们的和等于给定的目标值 target，并返回这两个数在数组中的下标。要求每个元素只能使用一次，且保证有且仅有一个解。 解题思路方法一：双层循环（暴力枚举）思路 通过双重循环遍历数组中的每一对元素，检查它们的和是否等于目标值 target。外层循环控制第一个元素的索引...