题意:一堆线段依次放在桌子上,上面的线段会压住下面的线段,求找出没被压住的线段. sol:从下向上找,如果发现上面的线段与下面的相交,说明被压住了.break掉 其实这是个n^2的算法,但是题目已经说了没被压住的线段不超过1000个,所以不会爆 #include<math.h> #include <stdio.h> #include <string.h> ]; int n; double X1,X2,Y1,Y2; #define eps 1e-8 #define PI…

#include<stdio.h> #include<math.h> const double eps=1e-8; int n; int cmp(double x) { if(fabs(x)<=eps)return 0; if(x<0)return -1; return 1; } struct Point { double x,y; Point (){} Point (double _x,double _y) { x=_x; y=_y; } Point operator…

http://poj.org/problem?id=1410 Intersection Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 11329   Accepted: 2978 Description You are to write a program that has to decide whether a given line segment intersects a given rectangle. An ex…

题目大意:有一个木棒,按照顺序摆放,求出去上面没有被别的木棍压着的木棍.....   分析:可以维护一个队列,如果木棍没有被压着就入队列,如果判断被压着,就让那个压着的出队列,最后把这个木棍放进队列,不过速度并不快,枚举才是最快的......据说是任意时刻没有超过1000个top sticks.....很难注意到.   代码如下: ===================================================================================…

Pick-up sticks Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 11884   Accepted: 4499 Description Stan has n sticks of various length. He throws them one at a time on the floor in a random way. After finishing throwing, Stan tries to fin…

Geometric Shapes Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 1243   Accepted: 524 Description While creating a customer logo, ACM uses graphical utilities to draw a picture that can later be cut into special fluorescent materials. To…

Pipe Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 8280   Accepted: 2483 Description The GX Light Pipeline Company started to prepare bent pipes for the new transgalactic light pipeline. During the design phase of the new pipe shape th…

Segments Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7739   Accepted: 2316 Description Given n segments in the two dimensional space, write a program, which determines if there exists a line such that after projecting these segments…

Treasure Hunt Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 4797   Accepted: 1998 Description Archeologists from the Antiquities and Curios Museum (ACM) have flown to Egypt to examine the great pyramid of Key-Ops. Using state-of-the-ar…

模板题 注意原题中说的线段其实要当成没有端点的直线.被坑了= = #include <cmath> #include <cstdio> #include <iostream> #include <cstring> using namespace std; #define eps 1e-8 #define PI acos(-1.0)//3.14159265358979323846 //判断一个数是否为0,是则返回true,否则返回false #define z…

链接:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=10 Area Time Limit: 2 Seconds      Memory Limit: 65536 KB      Special Judge Jerry, a middle school student, addicts himself to mathematical research. Maybe the problems he has thought are…

链接:http://poj.org/problem?id=1066 Treasure Hunt Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 5431   Accepted: 2246 Description Archeologists from the Antiquities and Curios Museum (ACM) have flown to Egypt to examine the great pyramid…

转载自 http://blog.csdn.net/william001zs/article/details/6213485 矢量 如果一条线段的端点是有次序之分的话,那么这种线段就称为 有向线段,如果有向线段p1p2的起点p1在坐标的原点,则可以把它称为矢量 p2 矢量的加减 设二维矢量 P = (x1, y1), Q = (x2, y2),则 P + Q = (x1 + x2, y1 + y2), P - Q = (x1 - x2, y1 - y2),且有 P + Q = Q + P, P -…

Segment set Problem Description A segment and all segments which are connected with it compose a segment set. The size of a segment set is the number of segments in it. The problem is to find the size of some segment set.   Input In the first line th…

http://poj.org/problem?id=2653 Pick-up sticks Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 9531   Accepted: 3517 Description Stan has n sticks of various length. He throws them one at a time on the floor in a random way. After finishi…

Pick-up sticks Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 10330   Accepted: 3833 Description Stan has n sticks of various length. He throws them one at a time on the floor in a random way. After finishing throwing, Stan tries to fin…

题目大意:在一个正方形的迷宫里有一些交错墙,墙的两端都在迷宫的边缘墙上面,现在得知迷宫的某个位置有一个宝藏,所以需要砸开墙来获取宝藏(只能砸一段墙的中点),问最少要砸开几面墙.   分析:这个题意刚开始理解错了,以为只能砸整面墙的中点,而实际上使一段墙的中点,也就是两个交点之间的墙,这样问题就变得比较容易了,中点的意义也就不存在了,因为所有的墙都是连接的边缘,所以如果从起点到终点连线有这堵墙,那么这堵墙一定无法绕过去,所以枚举所有的边缘点到终点有几面墙即可,注意不管怎样,边缘墙一定是要砸的.  …

Stan has n sticks of various length. He throws them one at a time on the floor in a random way. After finishing throwing, Stan tries to find the top sticks, that is these sticks such that there is no stick on top of them. Stan has noticed that the la…

题目大意:有一个不反光并且不透光的管道,现在有一束光线从最左端进入,问能达到的最右端是多少,输出x坐标.   分析:刚开始做是直接枚举两个点然后和管道进行相交查询,不过这样做需要考虑的太多,细节不容易掌控.后来发现其实只需要对接口进行一下相交查询就简单多了,因为只需要考虑能不能通过每个截口就可以了,而且这样做的好处还有没有平行线和重叠线的情况,因为所有的截口都是垂直于x轴的,换一种想法海阔太空啊.   代码如下: =========================================…

题目大意:有一个房间(左上角(0,10),右下角(10,0)),然后房间里有N面墙,每面墙上都有两个门,求出来从初始点(0,5),到达终点(10,5)的最短距离.   分析:很明显根据两点之间直线最短,所以所走的路线一定是点之间的连线,只需要判断一下这两点间知否有墙即可.   代码如下: =========================================================================================================…

#include<cstdio> #include<algorithm> #include<cstring> #include<cmath> #define eps 1e-8 using namespace std; bool dcmp(double x,double y) { if (fabs(x-y)>eps) return 1; return 0; } struct point { double x,y; point () {}; point (…

一定要注意位运算的优先级!!!我被这个卡了好久 判断线段相交模板题. 叉积,点积,规范相交,非规范相交的简单模板 用了“链表”优化之后还是$O(n^2)$的暴力,可是为什么能过$10^5$的数据? #include<cmath> #include<cstdio> #include<cstring> #include<algorithm> #define N 100005 using namespace std; struct Point { double x…

Pick-up sticks Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 7699   Accepted: 2843 Description Stan has n sticks of various length. He throws them one at a time on the floor in a random way. After finishing throwing, Stan tries to find…

// 线段相交 POJ 2653 // 思路:数据比较水,据说n^2也可以过 // 我是每次枚举线段,和最上面的线段比较 // O(n*m) // #include <bits/stdc++.h> #include <iostream> #include <cstdio> #include <cstdlib> #include <algorithm> #include <vector> #include <math.h>…

题目链接:POJ 3304 Problem Description Given n segments in the two dimensional space, write a program, which determines if there exists a line such that after projecting these segments on it, all projected segments have at least one point in common. Input…

POJ 2826 An Easy Problem?! -- 思路来自kuangbin博客 下面三种情况比较特殊,特别是第三种 G++怎么交都是WA,同样的代码C++A了 #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <cmath> using namespace std; const double eps = 1e-8;…

题意:给你n条线段依次放到二维平面上,问最后有哪些没与前面的线段相交,即它是顶上的线段 题解:数据弱,正向纯模拟可过 但是有一个陷阱:如果我们从后面向前枚举,找与前面哪些相交,再删除前面那些相交的线段,这样就错了 因为如果线段8与5,6,7相交了,我们接下来不能直接判断4,我们还要找7,6,5与之前哪些相交 #include<set> #include<map> #include<queue> #include<stack> #include<cmat…

题意:n根木棍随意摆放在一个平面上,问放在最上面的木棍是哪些. 思路:线段相交,因为题目说最多有1000根在最上面.所以从后往前处理,直到木棍没了或者最上面的木棍的总数大于1000. #include<stdio.h> #include<string.h> #include<math.h> #include<iostream> using namespace std; ; ; int sgn(double x){ ; ) ; ; } struct point…

Pick-up sticks Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 8862   Accepted: 3262 Description Stan has n sticks of various length. He throws them one at a time on the floor in a random way. After finishing throwing, Stan tries to find…

题目传送门 题意:就是小时候玩的一种游戏,问有多少线段盖在最上面 分析:简单线段相交,队列维护当前最上的线段 /************************************************ * Author :Running_Time * Created Time :2015/10/26 星期一 15:37:36 * File Name :POJ_2653.cpp ************************************************/ #inclu…