2016-08-15 题意:一面墙,往上面贴海报,后面贴的可以覆盖前面贴的.问最后能看见几种海报. 思路:可以理解成往墙上涂颜色,最后能看见几种颜色(下面就是以涂色来讲的).这面墙长度为1~1000 0000,一千万,确实很大.暴力的话肯定不行,除非..( you know). 正确的解法是用线段树,不过还得加上离散化,因为数据太大10000000啊. 先说一下离散化,这个其实就是压缩,把范围压缩,举个例子: 输入 : 1 3000    //涂第一种颜色 范围从1~10000      下面同…

离散化其实就是把所有端点放在一起,然后排序去个重就好了. 比如说去重以后的端点个数为m,那这m个点就构成m-1个小区间.然后给这m-1个小区间编号1~m-1,再用线段树来做就行了. 具体思路是,从最后一张的海报来判断,如果海报覆盖的区域有空白区域那么这张海报就是可见的.并及时更新线段树信息. 说一个我调了很久的才发现小错误,比如书2 2这样一个海报,如果你把这张海报的左右端点都记作2的话那就是个空区间了. 其实,这张海报覆盖的是第2块瓷砖.所以R++,2 3就表示第2块瓷砖的左右端点. 当然,如…

The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral posters at all places at their whim. The city council has finally decided to build an electoral wall for placing the…

[poj2528]Mayor's posters Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 66154   Accepted: 19104 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their elect…

Mayor's posters Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 62771   Accepted: 18120 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral post…

G - Mayor's posters POJ - 2528 这个题目要倒着来写,从后面往前面贴,因为前面的有些会被后面的覆盖. 所以我们就判断这张海报的位置有没有完全被覆盖,如果完全被覆盖了就不能贴,但是没有完全被覆盖就可以贴上去,然后更新掉这一段. #include <cstdio> #include <cstdlib> #include <cstring> #include <iostream> #include <queue> #incl…

由于坐标可能很大,此时需要离散化,将值转化为对应的坐标. #include<stdio.h> #include<algorithm> using namespace std; #define lson l,m,rt<<1 #define rson m+1,r,rt<<1|1 #define maxn 200010 ],sum[maxn*],ans; struct Node { int x; int y; }node[maxn]; ]; void pushup…

链接: http://poj.org/problem?id=2528 覆盖问题, 要从后往前找, 如果已经被覆盖就不能再覆盖了,否则就可以覆盖 递归呀递归什么时候我才能吃透你 代码: #include<stdio.h> #include<algorithm> #include<stdlib.h> #include<string.h> using namespace std; #define Lson r<<1 #define Rson r<…

线段树 + 离散化 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral posters at all places at their whim. The city council has finally decided to build an electoral…

Mayor's posters 转载自:http://blog.csdn.net/winddreams/article/details/38443761 [题目链接]Mayor's posters [题目类型]线段树+离散化 &题意: 给出一面墙,给出n张海报贴在墙上,每张海报都覆盖一个范围,问最后可以看到多少张海报 &题解: 海报覆盖的范围很大,直接使用数组存不下,但是只有最多10000张海报,也就是说最多出现20000个点,所以可以使用离散化,将每个点离散后,重新对给出控制的区间,这样…