题目链接:https://vjudge.net/problem/POJ-2528 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…

Mayor's posters Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 59239   Accepted: 17157 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral post…

题目链接:http://poj.org/problem?id=2528 题目: 题意:将n个区间进行染色(对于同一个区间,后一次染色会覆盖上一次的染色),问最后可见的颜色有多少种. 思路:由于区间长度太大,而n就1e4,假设每次要染色的区间端点值都不相同也就2n,所以我们可以将区间进行离散化,然后对区间进行建树(不是对1,n建树).我们在节点结构体内部用mx来记录最后这个节点的颜色,flag来标记这个区间内部的颜色是否完全一样,对于一个节点的flag的更新方法为判断它的左右子节点的flag是否都…

任意门:http://poj.org/problem?id=2528 Mayor's posters Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 77814   Accepted: 22404 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign hav…

题意: 在一面长度为10000000 的墙上贴广告,告诉你每张海报的l,r(1 <= li <= ri <= 10000000.),让你求最后有几张海报露出来 链接:http://poj.org/problem?id=2528 思路: 由于数据较大,直接开数组不现实,所以我们考虑将每个点离散化,由于这里可能存在原本不相邻的点在离散化后变成相邻 例如三张海报分别为1-5,1-2,4-5,将数据离散化后1,2,4,5分别对应1,2,3,4,此时我们发现用离散化之后的数据得出来的结果 是2,但…

/* poj 2528 Mayor's posters 线段树 + 离散化 离散化的理解: 给你一系列的正整数, 例如 1, 4 , 100, 1000000000, 如果利用线段树求解的话,很明显 会导致内存的耗尽.所以我们做一个映射关系,将范围很大的数据映射到范围很小的数据上 1---->1 4----->2 100----->3 1000000000----->4 这样就会减少内存一些不必要的消耗 建立好映射关系了,接着就是利用线段树求解 */ #include<ios…

恩,这区间范围挺大的,需要离散化.如果TLE,还需要优化一下常数. AC代码 #include <stdio.h> #include <string.h> #include <map> #include <set> #include <algorithm> using namespace std; +; typedef pair<int, int> Pii; Pii a[ + ]; +], c[maxn]; ]; void build…

题意 : 在墙上贴海报, n(n<=10000)个人依次贴海报,给出每张海报所贴的范围li,ri(1<=li<=ri<=10000000).求出最后还能看见多少张海报. 分析 : 很容易想到利用线段树来成段置换,最后统计总区间不同数的个数.但是这里有一个问题,就是区间可以很大,线段树开不了那么大的空间,遂想能不能离散化.实际上只记录坐标的相对大小进行离散化最后是不影响我们计算的,但是光是普通的离散化是不行的,就是我们贴海报的实际意义是对(l, r)段进行添加,而不是对于这个区间的点…

题目: 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…

题目 给定每张海报的覆盖区间,按顺序覆盖后,最后有几张海报没有被其他海报完全覆盖.离散化处理完区间端点,排序后再给相差大于1的相邻端点之间再加一个点,再排序.线段树,tree[i]表示节点i对应区间是哪张海报,如果是-1代表对应区间不是一张海报(0或多张).每贴一张海报,就用二分查找出覆盖的起点和终点对应的离散后的下标,然后更新区间.线段树的区间更新可以加上懒惰标记(或延迟标记,但是这题可以不用另外标记. #include<cstdio> #include<cstring> #in…

这道题最关键的点就在离散化吧. 假如有三张海报[1, 10] [10, 13][15,  20] 仅仅三个区间就得占用到20了. 但是离散化后就可以是[1, 2] [2, 3] [4, 5] n到1e4 不重叠的话最大也只到2e4 那么就可以做了 离散化技巧需要好好消化 代码如下 #include <cstring> #include <cstring> #include <cstdio> #include <algorithm> #define lp p&…

Mayor's posters Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 43507   Accepted: 12693 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral post…

http://poj.org/problem?id=2528 https://www.luogu.org/problem/UVA10587 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…

题目大意:有t组数据,每组数据给你n张海报(1<=n<=10000),下面n组数据分别给出每张海报的左右范围(1 <= l <= r <= 10000000),下一张海报会覆盖前一张海报,求最后可见(包括完全和不完全可见)的海报有几张. 例如: 1 5 1 4 2 6 8 10 3 4 7 10 如上图所示,答案为4. 解题思路:其实这是一道区间染色问题,但是由于查找区间太大,显然直接建树会导致MLE,所以这里通过使用对区间的离散化来缩小查找范围.参考了一些大牛博客,简单说一…

题目分析:线段树区间更新+离散化 代码如下: # include<iostream> # include<cstdio> # include<queue> # include<vector> # include<list> # include<map> # include<set> # include<cstdlib> # include<string> # include<cstring&g…

poj2528 Mayor's posters 题意:在墙上贴海报,海报可以互相覆盖,问最后可以看见几张海报 思路:这题数据范围很大,直接搞超时+超内存,需要离散化: 离散化简单的来说就是只取我们需要的值来用,比如说区间[1000,2000],[1990,2012] 我们用不到[-∞,999][1001,1989][1991,1999][2001,2011][2013,+∞]这些值,所以我只需要1000,1990,2000,2012就够了,将其分别映射到0,1,2,3,在于复杂度就大大的降下来了…

题目链接: 传送门 Mayor's posters Time Limit: 1000MS     Memory Limit: 65536K 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…

Mayor's posters Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 51175 Accepted: 14820 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral posters…

Mayor's posters Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 50888   Accepted: 14737 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral post…

POJ.2528 Mayor's posters (线段树 区间更新 区间查询 离散化) 题意分析 贴海报,新的海报能覆盖在旧的海报上面,最后贴完了,求问能看见几张海报. 最多有10000张海报,海报左右坐标范围不超过10000000. 一看见10000000肯定就要离散化了,因为建树肯定是建不下.离散化的方法是:先存到一个数组里面,然后sort,之后unique去重,最后查他离散化的坐标lower_bound就行了.特别注意如果是从下标为0开始存储,最后结果要加一.多亏wmr神犇提醒. 这题是…

Mayor's posters Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 70365   Accepted: 20306 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral post…

题意: 一共有n张海报, 按次序贴在墙上, 后贴的海报可以覆盖先贴的海报, 问一共有多少种海报出现过. 题解: 因为长度最大可以达到1e7, 但是最多只有2e4的区间个数,并且最后只是统计能看见的不同海报的数目,所以可以先对区间进行离散化再进行区间覆盖的操作. 由于墙上不贴东西的时候对后面没有影响, 所以可以不建树, 直接memset一下就好了. 因为是区域覆盖的问题, 树上原来的点并不会对后面的结果产生影响, 所以可以只修改lazy标记而不对树进行修改. 最后再用建树的操作访问一下lazy标记…

Mayor's posters Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 47905   Accepted: 13903 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral post…

Mayor's posters Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 64939   Accepted: 18770 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral post…

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…

Mayor's posters Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 74745   Accepted: 21574 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral post…

Mayor's posters 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 ele…

Mayor's posters Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Practice POJ 2528 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been plac…

Mayor's posters 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 ele…

Mayor's posters Time Limit: 1000MSMemory Limit: 65536K Total Submissions: 37346Accepted: 10864 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral posters at…