ZYB's Game Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=5592 Description ZYB has a premutation P,but he only remeber the reverse log of each prefix of the premutation,now he ask you to restore the premutation…

题意:给一个排列的每个前缀区间的逆序对数,让还原 原序列. 思路:考虑逆序对的意思,对于k = f[i] - f[i -1],就表示在第i个位置前面有k个比当前位置大的数,那么也就是:除了i后面的数字之外,它是在剩下的数字当中第k+1大的. 知道这个之后,可以用树状数组来帮助找出剩下的数中第k大的数,刚开始我们可以让1-n中每个元素都标记为1,那么他们的前缀和就代表它是第几小.所以,我们可以对于他们的和来二分快速寻找第k大数.其实在树状数组里面是按照第(i-k)小来找的.找完之后要删除这个元素的…

HDU 5862 Counting Intersections(离散化+树状数组) 题目链接http://acm.split.hdu.edu.cn/showproblem.php?pid=5862 Description Given some segments which are paralleled to the coordinate axis. You need to count the number of their intersection. The input data guarant…

Triple Time Limit: 12000/6000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 388    Accepted Submission(s): 148 Problem Description Given the finite multi-set A of n pairs of integers, an another finite multi-set B …

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…

Counting Intersections 题目链接: http://acm.split.hdu.edu.cn/showproblem.php?pid=5862 Description Given some segments which are paralleled to the coordinate axis. You need to count the number of their intersection. The input data guarantee that no two se…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1394 题目让你求一个数组,这个数组可以不断把最前面的元素移到最后,让你求其中某个数组中的逆序对最小是多少. 一开始就求原来初始数组的逆序对,树状数组求或者归并方法求(可以看<挑战程序设计>P178),然后根据最前面的元素大小递推一下每次移到最后得到的逆序数,取最小值. #include <iostream> #include <cstdio> #include <cs…

[题目链接] http://acm.hdu.edu.cn/showproblem.php?pid=5877 [题目大意] 给出一棵带权有根树,询问有几对存在祖先关系的点对满足权值相乘小于等于k. [题解] 我们沿根节点开始将点权加入权值树状数组,每次处理完子树就回溯,保证每个节点的答案统计是在只包括祖先节点的树状数组中进行. [代码] #include <cstdio> #include <algorithm> #include <vector> #include &l…

Sort it Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4672    Accepted Submission(s): 3244 Problem Description You want to processe a sequence of n distinct integers by swapping two adjacent s…

题目链接 Problem Description Given the finite multi-set A of n pairs of integers, an another finite multi-set B of m triples of integers, we define the product of A and B as a multi-set C=A∗B={⟨a,c,d⟩∣⟨a,b⟩∈A, ⟨c,d,e⟩∈B and b=e} For each ⟨a,b,c⟩∈C, its B…