Scrambled Polygon Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 10841   Accepted: 5085 Description A closed polygon is a figure bounded by a finite number of line segments. The intersections of the bounding line segments are called the…

http://poj.org/problem?id=2007 Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 6701   Accepted: 3185 Description A closed polygon is a figure bounded by a finite number of line segments. The intersections of the bounding line segments ar…

Space Ant Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 2876   Accepted: 1839 Description The most exciting space discovery occurred at the end of the 20th century. In 1999, scientists traced down an ant-like creature in the planet Y19…

链接:http://poj.org/problem?id=1696 Space Ant Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 3077   Accepted: 1965 Description The most exciting space discovery occurred at the end of the 20th century. In 1999, scientists traced down an a…

题意:平面上有n个点,一只蚂蚁从最左下角的点出发,只能往逆时针方向走,走过的路线不能交叉,问最多能经过多少个点. 思路:每次都尽量往最外边走,每选取一个点后对剩余的点进行极角排序.(n个点必定能走完,这是凸包的性质决定的) #include<stdio.h> #include<string.h> #include<math.h> #include<iostream> #include<algorithm> using namespace std;…

Space Ant Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 2489   Accepted: 1567 Description The most exciting space discovery occurred at the end of the 20th century. In 1999, scientists traced down an ant-like creature in the planet Y19…

从TLE的暴力枚举 到 13313MS的扫描线  再到 1297MS的简化后的扫描线,简直感觉要爽翻啦.然后满怀欣喜的去HDU交了一下,直接又回到了TLE.....泪流满面 虽说HDU的时限是2000MS 可是数据也忒强了点吧,真心给HDU跪了. 题意:给定平面上的N个点,属性分别标记为0和1,然后找一条直线,直线上的点全部溶解,一侧的1溶解,另一侧的0溶解.求出最多能溶解的点的个数. 思路:最直接的思路就是O(N^3)的暴力枚举,Discuss里面貌似有大牛过了,肯能是我太过暴力了吧,果断Tl…

平面上n个红点,m个黑点,问你多少个黑点至少在一个红三角形内. 对红点求凸包后,转化为询问有多少个黑点在凸包内. 点在凸多边形内部判定,选定一个凸包上的点作原点,对凸包三角剖分,将其他的点极角排序之后,使用二分法就可以判定点在哪个剖分出来的三角形的夹角内,然后用叉积即可判定其在凸包内还是外,O(logn): http://www.cnblogs.com/dream-wind/archive/2012/05/23/2514694.html #include<cstdio> #include<…

发现建图的方法各有不同,前面一题连边和这一题连边建图的点就不同,感觉这题的建图方案更好. 题意:给出每个婚礼的2个主持时间,每个婚礼的可能能会冲突,输出方案. 思路:n个婚礼,2*n个点,每组点是对称的,用O(n2)的方法判断每个点之间的关系来建图,然后通过拓扑排序输出即可. 代码: #include<iostream> #include<cstdio> #include<cstring> using namespace std; #define MAXN 2002 i…

Circle and Points Time Limit: 5000MS   Memory Limit: 30000K Total Submissions: 8346   Accepted: 2974 Case Time Limit: 2000MS Description You are given N points in the xy-plane. You have a circle of radius one and move it on the xy-plane, so as to enc…