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…

// 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>…

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…

Pick The Sticks Time Limit: 15000/10000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 593    Accepted Submission(s): 193 Problem Description The story happened long long ago. One day, Cao Cao made a special order c…

D - Pick The Sticks Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 无 Description The story happened long long ago. One day, Cao Cao made a special order called "Chicken Rib" to his army. No one got his point and all became very panic. However, Cao…

Pick The Sticks Time Limit: 15000/10000MS (Java/Others)     Memory Limit: 65535/65535KB (Java/Others) The story happened long long ago. One day, Cao Cao made a special order called "Chicken Rib" to his army. No one got his point and all became v…

D - Pick The Sticks Description The story happened long long ago. One day, Cao Cao made a special order called "Chicken Rib" to his army. No one got his point and all became very panic. However, Cao Cao himself felt very proud of his interesting…

Pick-up sticks Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 13377   Accepted: 5039 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…

题意: 按顺序扔木棒,求出最上层的木棒是哪些. 解法: 由于最上层的木棒不超过1000个,所以用一个队列存储最上层的木棒,每次扔出一个木棒后,都与队列中的木棒一一判断,看此木棒是否在某一最上层的木棒的上面,即判线段是否相交(两次跨立实验),如果相交,则将那个被压的木棒抛出队列,最后再加入扔的这个木棒到队列中. 代码: #include <iostream> #include <cstdio> #include <cstring> #include <cstdlib…

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…

题目链接:http://poj.org/problem?id=2653 Time Limit: 3000MS Memory Limit: 65536K 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 the top sticks, that…

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…

题目链接 题意 : 把每根棍往地上扔,找出最后在上面的棍,也就是说找出所有的没有别的棍子压在它的上面的棍子. 思路 : 对于每根棍子,压在他上面的棍子一定是在它之后扔的棍子,所以在找的时候只要找它之后的线段是否与他相交即可. #include <stdio.h> #include <iostream> #include <math.h> #include <string.h> using namespace std ; struct point { doub…

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…

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: 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…

判断线段与线段相交 莫名其妙的数据量 #include <iostream> #include <cstdio> #include <vector> #include <cmath> #include <cstring> using namespace std; ; int dcmp(double x) { : (x < ? - : ); } struct Point { double x,y; Point(, ) : x(a), y(b)…

题意:给定n个木棍依次放下,要求最终判断没被覆盖的木棍是哪些. 思路:快速排斥以及跨立实验可以判断线段相交. #include<algorithm> #include<cstdio> #include<cmath> #include<cstring> #include<iostream> ; struct Point{ double x,y; Point(){} Point(double x0,double y0):x(x0),y(y0){} }…

计算几何,判断线段相交 注意题目中的一句话:You may assume that there are no more than 1000 top sticks. 我认为是没有描述清楚的,如果不是每次扔完都保证不超过1000,此题很难做吧. 如果每次扔完保证小于1000根在顶部,那么暴力即可. 开一个vector保存每次扔完在顶部的棒子,下一次扔的时候,只要在删除vector中与扔的相交的棒子,然后再把这个棒子压入进来,最后留下的就是答案 #include<cstdio> #include&l…

Pick-up sticks Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 12861   Accepted: 4847 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…

Pick-up sticks Time Limit: 3000MS Memory Limit: 65536K 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 the top sticks, that is these sticks such…

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 the top sticks, that is these sticks such that there is no stick on top of them. Stan has noticed…

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…

Area Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 5811   Accepted: 2589 Description Being well known for its highly innovative products, Merck would definitely be a good target for industrial espionage. To protect its brand-new resear…

题目大意:一个小孩不断往地上扔棍子,共n根,求结束后共有多少根不与去他相交. 解法思路:典型的判断线段相交问题,利用快速排斥+双跨立判断相交,最后输出没相交的. (图片来源:http://www.2cto.com/kf/201308/237246.html) #include<iostream> #include<algorithm> using namespace std; ; ; struct Point { double x, y; }s[nMax], e[nMax]; do…

/* 最小生成树 + 几何判断 Kruskal 球心之间的距离 - 两个球的半径 < 0 则说明是覆盖的!此时的距离按照0计算 */ #include<iostream> #include<cstdio> #include<cstring> #include<cmath> #include<algorithm> using namespace std; ]; struct ball{ double x, y, z, r; }; struct…

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…

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…

#include <iostream> #include <cstring> #include <algorithm> #include <cmath> #include <cstdio> using namespace std; struct point { double x,y; }; point be[],en[]; ]; ]; double max(double a,double b){ return a>b?a:b; } doub…