In combinatorial mathematics, a derangement is a permutation of the elements of a set, such that no element appears in its original position. There's originally an array consisting of n integers from 1 to n in ascending order, you need to find the nu…

Given an array of integers, 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once. Find all the elements that appear twice in this array. Could you do it without extra space and in O(n) runtime? Example: Input: [4,3,2,7,…

Given a sorted array consisting of only integers where every element appears twice except for one element which appears once. Find this single element that appears only once. Example 1: Input: [1,1,2,3,3,4,4,8,8] Output: 2 Example 2: Input: [3,3,7,7,…

Let's call an array A a mountain if the following properties hold: A.length >= 3 There exists some 0 < i < A.length - 1 such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1] Given an array that is definitely…

题目标签:Array 题目给了我们一组 从小到大的 integers,让我们平方数字 并且 也排序成 从小到达. 因为有负数在里面,平方后,负数在array的位置会变动. 可以设left 和 right pointers,从两边遍历,比较一下两个平方后的数字,把大的那个 放入新建的array的末尾. 具体看code. Java Solution: Runtime beats 100.00% 完成日期:02/03/2019 关键点:two pointers class Solution { pub…

Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.…

Remove Duplicates from Sorted Array Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory.…

Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.…

Given a sorted array nums, remove the duplicates in-place such that duplicates appeared at most twice and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra mem…

This is a follow up problem to Search in Rotated Sorted Array, where nums may contain duplicates. 思路 该题是[leetcode]33. Search in Rotated Sorted Array旋转过有序数组里找目标值 的followup 唯一区别是加了line24-26的else语句来skip duplicates 代码 class Solution { public boolean sear…