摘要：
快速选择算法,是一种能在大致O(N)的时间内选取数组中第k大或者k小的算法.其基本思路与快速排序算法类似,也是分治的思想. 其实这个算法是个基础算法,但是不常用,所以今天编的时候错了POJ2388,才有了这篇文章. 下面几段代码,尤其要注意的是 while(i<j) 还是 while(i<=j) 程 阅读全文
摘要：
Find the kth largest element in an unsorted array. Note that it is the kth largest element in the sorted order, not the kth distinct element. For exam 阅读全文
摘要：
Given a non-empty array of integers, return the k most frequent elements. For example,Given [1,1,1,2,2,3] and k = 2, return [1,2]. Note: You may assum 阅读全文
摘要：
Given two arrays, write a function to compute their intersection. Example:Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2, 2]. Note: Each elemen 阅读全文
摘要：
Given two arrays, write a function to compute their intersection. Example:Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2]. Note: Each element i 阅读全文
摘要：
All DNA is composed of a series of nucleotides abbreviated as A, C, G, and T, for example: "ACGAATTCCG". When studying DNA, it is sometimes useful to 阅读全文