Your task is to determine how many swap operations Ultra-QuickSort needs to perform in order to sort a given input sequence. Input The input contains several test cases. Every test case begins with a line that contains a single integer n < 500,000 -- the length of the input sequence. E...
归并排序求逆序对。 poj 2299
Your task is to determine how many swap operations Ultra-QuickSort needs to perform in order to sort a given input sequence. Input The input contains several test cases. Every test case begins with a line that contains a single integer n < 500,000 -- the length of the input sequence. E...
poj2299 Ultra-QuickSort 题解报告 题目传送门 【题目大意】 给定一个长度为nn的序列aa,在只允许交换相邻两个数的情况下,求至少需要交换多少次才能使得aa从小到大排序。 【思路分析】 这题的实质是冒泡排序法的过程,每交换一次就会使整个序列的逆序对减少1,最后整个序列的逆序对个数为0,即题目的答案为序列中的...
POJ2299-Ultra-QuickSort 解题心得 原题: Description In this problem, you have to analyze a particular sorting algorithm. The algorithm processes a sequence of n distinct integers by swapping two adjacent sequence elements until the sequence is sorted in ascending order. For the input sequence...
poj2299解题报告(归并排序求逆序数) POJ 2299,题目链接http://poj.org/problem?id=2299 题意: 给出长度为n的序列,每次只能交换相邻的两个元素,问至少要交换几次才使得该序列为递增序列。 思路: 其实就是求逆序数,那么直接向到的就是冒泡了,交换一次,记录一次即可。但是n的范围达到50W,冒泡O(n^2)的复杂度...