思路: 1.线段树 逆着插入就OK了 2.块状链表 (可是我并不会写) //By SiriusRen #include <cstdio> #include <cstring> #include <algorithm> using namespace std; int n,xx,tree[1000050],cnt[1000050]; struct Node{int num,wei;}node[1000050]; void build(int l,int r,int pos…

Buy Tickets Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 18561   Accepted: 9209 Description Railway tickets were difficult to buy around the Lunar New Year in China, so we must get up early and join a long queue… The Lunar New Year wa…

http://poj.org/problem?id=2828 学到的思维: 1.变化的或者后来的优先影响前面的,那么从最后一个往前看,最后一个就成了 确定的, 而且后来的也能够确定----假设从前往后,全部的随时都不是确定的 2.线段树叶子节点直接维护区间(线段)信息,非叶子节点v维护的是以v为树根的整个子树的信息,那么假设父节点rt信息为[l,r]那么左子树维护[l,mid],右子树维护[mid+1,r]的信息.假设假设是前缀和,rt里是1-n的和,左子树1~n/2的和,右子树是n/2+1~n…

Buy Tickets Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 15422   Accepted: 7684 Description Railway tickets were difficult to buy around the Lunar New Year in China, so we must get up early and join a long queue… The Lunar New Year wa…

http://poj.org/problem?id=2828 插队问题,n个人,下面n行每行a,b表示这个人插在第a个人的后面和这个人的编号为b,最后输出队伍的情况 涉及到节点的问题可以用到线段树,这里因为每个人插队时有顺序的,如果按照正着的顺序来情况太复杂,所以可以试试倒过来,从最后一个人开始,此时找到的位置 一定是最终位置,这样就很简单了,   结构体中多开一个mark表示每个区间的空位置,多开一个sum表示人的编号 这道题不错,提醒我们有时候换一换思路,逆向思考一下 #include<cs…

Ultra-QuickSort Time Limit: 7000MS Memory Limit: 65536K Total Submissions: 50737 Accepted: 18595 Description In this problem, you have to analyze a particular sorting algorithm. The algorithm processes a sequence of n distinct integers by swapping tw…

题目大意:依次描述了一个N个人的队伍,每个人所站的序号以及他的价值,依次描述每个人的过程中,存在序号相同的人,表示该人插入到了前一个序号相同的人的前面.最后输出整个队伍的值排列情况. 这个题目确实难以想到居然可以用线段树做,之前还脑残去敲什么链表,结果发现链表这玩意儿真不是一般的垃圾,好多地方根本就无法对时间进行优化. 当然了,就算告诉了你用线段树做,可能还是会很头疼,这里涉及插队操作..而且线段树具体是存放什么东西的呢 线段树就是为了模拟当前队伍的空位数,比如一个4人队伍,Root肯定是值为4…

倒着插,倒着插,这道题是倒着插! 想一下如果 Posi 里面有若干个0,那么排在最前面的一定是最后一个0. 从后往前看,对于第i个数,就应该插在第Posi + 1个空位上,所以用线段树来维护区间空位的个数. 说一下那个坑爹的第56行的判断: if(i > 1) printf(" "); 将输出的n个数用空格隔开,我感觉这是一个还算常用的写法啊,结果各种莫名TLE,加上输入挂也补救不回来. 去掉这个无谓的判断后,3594MS险过,加上输入挂3094MS,还算是起到了一定的加速作用.…

Description: Railway tickets were difficult to buy around the Lunar New Year in China, so we must get up early and join a long queue… The Lunar New Year was approaching, but unluckily the Little Cat still had schedules going here and there. Now, he h…

Description Railway tickets were difficult to buy around the Lunar New Year in China, so we must get up early and join a long queue- The Lunar New Year was approaching, but unluckily the Little Cat still had schedules going here and there. Now, he ha…