3743 -- LL’s cake 搞了好久都过不了,看了下题解是用PSLG来做的.POJ 2164 && LA 3218 Find the Border (Geometry, PSLG 平面直线图) - LyonLys - 博客园 这篇里面写过一下,就是把点都提取出来,然后模拟沿着边界移动,找到多边形并计算面积. 而我的做法是直接模拟多边形切割,各种超时爆内存.先留着,看以后能不能用这个来过. 没过的代码: #include <cstdio> #include <cst…

题意是给你一块在原点半径为10的圆,然后告诉你一条直线在圆弧上的极角,相当于用这条直线把这个圆分成两半,然后一共是n条直线切圆,就好比切蛋糕,问你其中最大一块的面积是多少. 如果我们将圆弧转化成直线边,那么这个题就变成PSLG裸题,但是这里是圆弧,所以我们需要将其转化. 我先将所有在圆上的点记录下来,最后极角排序,绕一周,这些点分割出来肯定会有一部分算面积的时候是要算上那部分弓型面积,但是有一部分不是,主要是这部分面积仅仅就是这块弓型面积,没有其他多边形面积,例如样例3,为了避免这种问题,我们可…

POJ 2828 Buy Tickets(排队问题,线段树应用) ACM 题目地址:POJ 2828 Buy Tickets 题意:  排队买票时候插队.  给出一些数对,分别代表某个人的想要插入的位置Pos_i和他的Val_i,求出最后的队列的val顺序. 分析:  也是一道非常巧妙的题目.  刚開始天真的以为sort一下即可了.wa了一发后发现我错了...  原来能够非常巧妙的用线段树做.因为某个人想要插入posi位置,插入后他就在posi位置上了,可是可能其它人会插到他前面来,他的位置就会…

POJ 2135 Farm Tour (网络流,最小费用最大流) Description When FJ's friends visit him on the farm, he likes to show them around. His farm comprises N (1 <= N <= 1000) fields numbered 1..N, the first of which contains his house and the Nth of which contains the b…

POJ 2516 Minimum Cost (网络流,最小费用流) Description Dearboy, a goods victualer, now comes to a big problem, and he needs your help. In his sale area there are N shopkeepers (marked from 1 to N) which stocks goods from him.Dearboy has M supply places (marke…

Candies Time Limit: 1500MS   Memory Limit: 131072K Total Submissions: 20067   Accepted: 5293 Description During the kindergarten days, flymouse was the monitor of his class. Occasionally the head-teacher brought the kids of flymouse’s class a large b…

Wormholes Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 24249   Accepted: 8652 Description While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way pa…

http://poj.org/problem?id=2175 Evacuation Plan Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 3256   Accepted: 855   Special Judge Description The City has a number of municipal buildings and a number of fallout shelters that were build…

Labeling Balls Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 10161   Accepted: 2810 Description Windy has N balls of distinct weights from 1 unit to N units. Now he tries to label them with 1 toN in such a way that: No two balls share…

Graveyard Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 1707   Accepted: 860   Special Judge Description Programming contests became so popular in the year 2397 that the governor of New Earck — the largest human-inhabited planet of the…