In the Quicksort challenges, you sorted an entire array. Sometimes, you just need specific information about a list of numbers, and doing a full sort would be unnecessary. Can you figure out a way to use your partition code to find the median in an a…
题目简述: There are two sorted arrays A and B of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)). 解题思路: 这本身是个很简单的题目,但是题目要求他的复杂度为O(log(m+n)),就很有难度了.不过首先我们还是可以明确我们要用分治法.关键是怎么分治呢?我们…
https://leetcode.com/problems/median-of-two-sorted-arrays/ There are two sorted arrays nums1 and nums2 of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)). Example 1: nums1 =…
There are two sorted arrays A and B of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)). 思路: 难,知道用分治算法,却不知道怎么用.只好看答案. 基本的思路是如果中位数是第K个数,A[i]如果是中位数,那么A[i]已经大于了i个数,还应大于K - i - 1个…
题目链接:Running Time of Quicksort Challenge In practice, how much faster is Quicksort (in-place) than Insertion Sort? Compare the running time of the two algorithms by counting how many swaps or shifts each one takes to sort an array, and output the dif…
在jxzz上发现的一个做题网站,每周都有训练题,题目质量……前三题比较水,后面好神啊,而且类型差不多,这周似乎是计数专题…… Army Game 然后给出n*m,问需要多少个小红点能全部占领 解法:乘法... Best Divisor 给一个数,问一个数的约数中数字和最大的约数. 解法:直接分解质因数就可以啦. Twins 孪生质数定义为两个质数之差为2,问n,m之间有多少个孪生质数(n<=m<=10^9,m-n<=10^6) 解法:显然直接判断区间内相邻的两个奇数是否为质数就可以啦.然…
题意 给出一个长度为n的有序序列.给出m个询问,每个询问包括四个正整数l1,r1,l2,r2你用l1tor1的和l2tor2的元素来组成一个新的序列,然后找出这个序列的中位数. 分析 这是当时Spring Team Training D 的一道题,显而易见的模拟,我当时在场上写了190行. 赛后看了学长的代码后···orzzzzz!! 我当时分类的时候是把 “相交不包含(l2<r1&&r2>r1)”,和“包含(r2<r1)”作为两种情况来写.然而事实上,如果是包含,只需要…