题目 Rotate an array of n elements to the right by k steps. For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4]. Note: Try to come up as many solutions as you can, there are at least 3 different ways to solve this…

题目 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 andk=2, return 4−>5−>1−>2−>3−>NULL. 分析 给定一个链表,以及一个整数k,返回链表右旋k个元素后的结果. 要使得链表右旋k个元素,也就是说明链表后(k)个元素将成为新链表…

Rotate an array of n elements to the right by k steps. For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4]. 题目: 给一数组,n个元素,将数组向右移动循环移动k个元素. 思路: 注意题目的要求是循环移动,所以k可以是任意非负整数,但数组元素个数为n,因此k=k%n. 一种通用的思路就是: 1.翻转整个数组 :A[…

题目 You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). Follow up: Could you do this in-place? 分析 本地使得二维矩阵,旋转90角度. 通过实际数据分析,通过两个步骤的元素交换可实现目标: 按照主对角线,将对称元素交换 按照列,将对称列元素全部交换 即可达到,使得二维矩阵,本地旋转90个角度. AC代码 cla…

题目 Follow up for "Find Minimum in Rotated Sorted Array": What if duplicates are allowed? Would this affect the run-time complexity? How and why? Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 migh…

题目 Follow up for H-Index: What if the citations array is sorted in ascending order? Could you optimize your algorithm? 分析 同LeetCode(274)H-Index第二个版本,给定引用数量序列为递增的:这就省略了我们的第一个排序步骤: O(n)的时间复杂度,遍历一次即可. AC代码 class Solution { public: int hIndex(vector<int>…

题目 Given an array of integers, find out whether there are two distinct indices i and j in the array such that the difference between nums[i] and nums[j] is at most t and the difference between i and j is at most k. 分析 题目描述:给定一个整数序列,查找是否存在两个下标分别为i和j的元…

题目 Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and sell one share of the stock multiple times).…

题目 Given a binary tree struct TreeLinkNode { TreeLinkNode *left; TreeLinkNode *right; TreeLinkNode *next; } Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL. Initially,…

题目 Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. For example: Given the below binary tree and sum = 22, 分析 本题目与上一题LeetCode(112) Path Sum虽然类型相同,但是需要在以前的基础上,多做处理一些: 与Path Sum相比,本题是求出路径,所以,在找到满足的路…