LeetCode 22: Generate Parentheses
Problem DescriptionGiven n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.Example 1Input: n = 3 Output: ["((()))","(()())","(()
LeetCode 21: Merge Two Sorted Lists
Problem DescriptionYou are given the heads of two sorted linked lists list1 and list2.Merge the two lists in a one sorted list. The list should be made by splicing together the nodes of the first two
LeetCode 17: Letter Combinations of a Phone Number
Problem DescriptionGiven a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. Return the answer in any order.A mapping of digits to l
LeetCode 15: Sum
Problem DescriptionGiven an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, and nums[i] + nums[j] + nums[k] == 0.Notice that the solution
LeetCode 11: Container With Most Water
Problem DescriptionYou are given an integer array height of length n. There are n vertical lines drawn such that the two endpoints of the ith line are (i, 0) and (i, height[i]).Find two lines that tog
LeetCode 5: Longest Palindromic Substring
Problem DescriptionGiven a string s, return the longest palindromic substring in s.Example 1Input: s = "babad" Output: "bab" Explanation: "aba" is also a valid answer.Exa
LeetCode 4: Median of Two Sorted Arrays
Problem DescriptionGiven two sorted arrays nums1 and nums2 of size m and n respectively, return the median of the two sorted arrays.The overall run time complexity should be O(log (m+n)).Example 1Inpu
LeetCode 1: Two Sum
Problem DescriptionGiven an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.You may assume that each input would have exactly one soluti
Java Quick Cheatsheet
Java Data TypesPrimitive Data Typesbyteshortintlongfloat: ~6-7 decimal digitsdouble: 15 decimal digitschar: surrounded by single quotesbooleanNotes:End the value with an "f" for floats and "d" for dou
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在以为人民服务为宗旨的国家，在面对新冠疫情的时候，人民正是需要药物治疗的时候，为什么不增加药物（感冒、发烧）的供应量、优化人民群众买药的途径更利于买药，反而是禁止这些药物购买？是要人民自生自灭，还是这时候不害怕医疗资源挤兑了？为什么不能让人民群众在生病最早期的时候先行治疗？在人民民主的国家，在面对新冠疫情的时候，从2020到2022年，三年了，国外疫苗早已不在紧缺，为什么不及时引进国外mRNA的疫