inversion就是逆序对 题目:现给出一个数列,求该数列中的逆序对数(逆序数).本节给出三种方法:方法一是最直接的暴力方法:方法二是基于归并分治的思想:方法三是基于线段树的.   [解法一] 暴力方法最直接,也最容易想到,两层for循环就可以算出来逆序数:每遇到一个元素回头遍历寻找比其大的元素个数即可,当然向后寻找比其小的元素个数也可以,复杂度为O(n^2),代码: 1 2 3 4 5 6 7 8 9 10 11 12 int sum = 0; for(int i = 0; i < size…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1394 Minimum Inversion Number                        Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)                                            Total Submission(s): 10…

OpenCASCADE Root-Finding Algorithm eryar@163.com Abstract. A root-finding algorithm is a numerical method, or algorithm, for finding a value x such that f(x)=0, for a given function f. Such an x is called a root of the function f. In OpenCASCADE math…

题目链接: 传送门 Minimum Inversion Number Time Limit: 1000MS     Memory Limit: 32768 K Description The inversion number of a given number sequence a1, a2, ..., an is the number of pairs (ai, aj) that satisfy i < j and ai > aj. For a given sequence of numbe…

Description For sequence i1, i2, i3, … , iN, we set aj to be the number of members in the sequence which are prior to j and greater to j at the same time. The sequence a1, a2, a3, … , aN is referred to as the inversion sequence of the original sequen…

Inversion Sequence Time Limit:2000MS     Memory Limit:262144KB     64bit IO Format:%lld & %llu Description For sequence i1, i2, i3, … , iN, we set aj to be the number of members in the sequence which are prior to j and greater to j at the same time.…

C - Minimum Inversion Number Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Description The inversion number of a given number sequence a1, a2, ..., an is the number of pairs (ai, aj) that satisfy i < j and ai > aj.…

Problem Description The inversion number of a given number sequence a1, a2, ..., an is the number of pairs (ai, aj) that satisfy i < j and ai > aj. For a given sequence of numbers a1, a2, ..., an, if we move the first m >= 0 numbers to the end of…

承接上一章,接着写Genetic Algorithm. 本章主要写排列表达(permutation representations) 开始先引一个具体的例子来进行表述 Outline 问题描述 排列表达的变异算子 排列表达的重组算子 种群模型 父辈选择 1. 问题描述 旅行商问题.给定n个城市,旅行商需要拜访所有城市后回到原点.要求每个城市只能拜访一次,问题的最终目标是寻找一个最短的路线. Encoding: 将所有的城市标上序号:1,2,...,n.比如n=4,那么排列可以为[1,2,3,4]…

Inversion Sequence Problem's Link:   http://acm.csu.edu.cn/OnlineJudge/problem.php?id=1555 Mean: 给你一个序列a[n],要你按照要求去构造一个序列b. 序列a[i]表示序列b中的i前面有a[i]个数比i大. 转换一下就是: 已知一个连续的序列(1,2,3,4,...),然后告诉了我们这个序列中每个数前面比本身大的个数,根据这些条件将这个序列调整顺序,找到满足条件的序列. analyse: STL大法好…