Minimum Inversion Number Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 16686    Accepted Submission(s): 10145 Problem Description The inversion number of a given number sequence a1, a2, ..., a…

为什么线段树能够求逆序数? 给一个简单的序列 9 5 3 他的逆序数是3 首先要求一个逆序数有两种方式:能够从头開始往后找比当前元素小的值,也能够从后往前找比当前元素大的值,有几个逆序数就是几. 线段树就是应用从后往前找较大值得个数.(一边更新一边查) 当前个数是 n = 10 元素   9  5   3 9先增加线段树,T[9]+=1:查从T[9]到T[10]比9大的值,没有sum = 0. 5 增加线段树.T[5] += 1.查从T[5]到T[10]比5大的值.有一个9.sum +=1: 3…

Minimum Inversion Number Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 10326 Accepted Submission(s): 6359 Problem Description The inversion number of a given number sequence a1, a2, ..., an is t…

<题目链接> 题意描述: 给你一个有0--n-1数字组成的序列,然后进行这样的操作,每次将最前面一个元素放到最后面去会得到一个序列,那么这样就形成了n个序列,那么每个序列都有一个逆序数,找出其中最小的一个输出! 解题分析: 先利用线段树求出初始序列的逆序数,这里有一个非常巧妙的地方,由于比a[i]大的数是离散且连续的,所以可以用线段树来实现(与线段树节点的区间特性符合). #include <bits/stdc++.h> using namespace std; #define L…

一.题目描述 There is a permutation P with n integers from 1 to n. You have to calculate its inversion number, which is the number of pairs of Pi and Pj satisfying the following conditions: iPj. 二.输入 The input may contain several test cases. In each test c…

Minimum Inversion Number Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 15675 Accepted Submission(s): 9569 Problem Description The inversion number of a given number sequence a1, a2, -, an is the…

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 the seq…

题目大意: 随机给你全排列中的一个,但不断的把第一个数丢到最后去,重复N次,形成了N个排列,问你这N个排列中逆序数最小为多少 做法: 逆序数裸的是N^2 利用线段树可以降到NlogN 具体方法是插入一个数,查询之前比他大的数有多少个,即query(A[i]+1,N,1,N,1),利用线段树保存区间和即可: 至于不断把一个数丢到最后,可以用O(1)的时间来处理 即  temp=temp-A[i]+(N-A[i]-1);  这个地方很容易思考的 不解释了 完整代码如下: /* 1.WA 忘记初始化线…

Brainman Time Limit: 1000 MS Memory Limit: 30000 KB 64-bit integer IO format: %I64d , %I64u   Java class name: Main [Submit] [Status] [Discuss] Description Background Raymond Babbitt drives his brother Charlie mad. Recently Raymond counted 246 toothp…

Minimum Inversion Number Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 11788    Accepted Submission(s): 7235 Problem Description The inversion number of a given number sequence a1, a2, ..., an…