IncredibleThings

摘要： Given a list, rotate the list to the right by k places, where k is non-negative. For example: Given 1->2->3->4->5->NULL and k = 2, return 4->5->1->2->3->NULL. /** * Definition for singly-linked l... 阅读全文

摘要： 二刷：注意能把containsKey用在object上的条件 阅读全文

摘要： Given a collection of numbers that might contain duplicates, return all possible unique permutations. For example, [1,1,2] have the following unique permutations: [ [1,1,2], [1,2,1], [2,1,1] ]... 阅读全文

摘要： Given a collection of distinct numbers, return all possible permutations. For example, [1,2,3] have the following permutations: [ [1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], [3,2,1] ] ... 阅读全文

摘要： Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. Each number in C may only be used once in the combinatio... 阅读全文

摘要： 对于这种backtracking的题目， 还是得了解选择，限制，和结束的条件分别是什么。 阅读全文

摘要： Given a sorted array of integers, find the starting and ending position of a given target value. Your algorithm's runtime complexity must be in the order of O(log n). If the target is not found in ... 阅读全文

摘要： 二刷解法： 阅读全文

摘要： 注意处理while的边界问题。 阅读全文

摘要： 所谓Backtracking都是这样的思路：在当前局面下，你有若干种选择。那么尝试每一种选择。如果已经发现某种选择肯定不行（因为违反了某些限定条件），就返回；如果某种选择试到最后发现是正确解，就将其加入解集所以你思考递归题时，只要明确三点就行：选择 (Options)，限制 (Restraints) 阅读全文