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…

题目链接 http://poj.org/problem?id=2528 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 dec…

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: 45703   Accepted: 13239 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…

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 wall for…

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 wall for…

题目链接:http://poj.org/problem?id=2528 给你n块木板,每块木板有起始和终点,按顺序放置,问最终能看到几块木板. 很明显的线段树区间更新问题,每次放置木板就更新区间里的值.由于l和r范围比较大,内存就不够了,所以就用离散化的技巧 比如将1 4化为1 2,范围缩小,但是不影响答案. 写了这题之后对区间更新的理解有点加深了,重点在覆盖的理解(更新左右两个孩子节点,然后值清空),还是要多做做题目. #include <iostream> #include <cst…

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…

Mayor's posters Time Limit: 1 Sec  Memory Limit: 256 MB 题目连接 http://poj.org/problem?id=2528 Description The citizens of Bytetown, AB, could not stand that the candidates in the mayoral election campaign have been placing their electoral posters at al…