HDU 5533 Dancing Stars on Me(判断n个整数点是否能组成正n边形)——2015ACM/ICPC亚洲区长春站
来源:互联网 发布:淘宝购买叶罗丽娃娃 编辑:程序博客网 时间:2024/05/01 05:50
Dancing Stars on Me
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 262144/262144 K (Java/Others)
Problem Description
The sky was brushed clean by the wind and the stars were cold in a black sky. What a wonderful night. You observed that, sometimes the stars can form a regular polygon in the sky if we connect them properly. You want to record these moments by your smart camera. Of course, you cannot stay awake all night for capturing. So you decide to write a program running on the smart camera to check whether the stars can form a regular polygon and capture these moments automatically.
Formally, a regular polygon is a convex polygon whose angles are all equal and all its sides have the same length. The area of a regular polygon must be nonzero. We say the stars can form a regular polygon if they are exactly the vertices of some regular polygon. To simplify the problem, we project the sky to a two-dimensional plane here, and you just need to check whether the stars can form a regular polygon in this plane.
Formally, a regular polygon is a convex polygon whose angles are all equal and all its sides have the same length. The area of a regular polygon must be nonzero. We say the stars can form a regular polygon if they are exactly the vertices of some regular polygon. To simplify the problem, we project the sky to a two-dimensional plane here, and you just need to check whether the stars can form a regular polygon in this plane.
Input
The first line contains a integer T indicating the total number of test cases. Each test case begins with an integer n , denoting the number of stars in the sky. Following n lines, each contains 2 integers xi,yi , describe the coordinates of n stars.
1≤T≤300
3≤n≤100
−10000≤xi,yi≤10000
All coordinates are distinct.
All coordinates are distinct.
Output
For each test case, please output "`YES`" if the stars can form a regular polygon. Otherwise, output "`NO`" (both without quotes).
Sample Input
330 01 11 040 00 11 01 150 00 10 22 22 0
Sample Output
NOYESNO
题意:给你n个整点的坐标,问是否能组成正n边形。
解题思路:其实这道题,做过bestcoder的人应该多多少少有些印象吧,有一道类似的题,只不过那时候只问能不能组成正三角形、正方形、正五边形和正六边形,具体可查看链接
HDU 5365 Run ——BestCoder Round #50(div.1 div.2)
所以我们便可以得到格点(即整点,就是横纵坐标均为整数)只能构成正方形的结论
这么说来,我们只需要注意n=4才有可能是正n边形
也就是说只要我们判断4个点能不能组成正方形就可以了
#pragma comment(linker, "/STACK:1024000000,1024000000")#include<stdio.h>#include<string.h>#include<stdlib.h>#include<queue>#include<stack>#include<math.h>#include<vector>#include<map>#include<set>#include<stdlib.h>#include<cmath>#include<string>#include<algorithm>#include<iostream>#define exp 1e-10using namespace std;const int N = 105;const int M = 2010;const int inf = 2147483647;const int mod = 2009;int x[N],y[N],L[6];int main(){ int t,i,j,n,k; scanf("%d",&t); while(t--) { scanf("%d",&n); for(i=0;i<n;i++) scanf("%d%d",&x[i],&y[i]); if(n!=4) { puts("NO"); continue; } for(k=i=0;i<n;i++) for(j=0;j<i;j++,k++) L[k]=(x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]); sort(L,L+6); if(L[0]==L[1]&&L[2]==L[1]&&L[2]==L[3]&&L[4]==L[5]&&L[4]!=L[3]) puts("YES"); else puts("NO"); } return 0; }菜鸟成长记
0 0
- HDU 5533 Dancing Stars on Me(判断n个整数点是否能组成正n边形)——2015ACM/ICPC亚洲区长春站
- [hdu 5533][2015ACM/ICPC亚洲区长春站] Dancing Stars on Me 计算几何
- hdu 5533 Dancing Stars on Me 2015ACM/ICPC亚洲区长春站-重现赛
- HDU 5533 Dancing Stars on Me (2015ACM/ICPC亚洲区长春 &&计算几何)
- hdu 5533 Dancing Stars on Me 【2015ACM/ICPC亚洲区长春站-重现赛(感谢东北师大)】
- 【hdu5533】【2015ACM/ICPC亚洲区长春站】Dancing Stars on Me 题意&题解&代码
- HDU 5533 Dancing Stars on Me(整数坐标能否构成正n变形)
- HDOJ 5533 Dancing Stars on Me (判断点是否能组成正多边形)
- HDU5533 Dancing Stars on Me(极角排序+判断正n边形)
- G-Dancing Stars on Me(2015ACM-ICPC长春站)
- HDU 5531 Rebuild ——— 2015ACM-ICPC亚洲区长春站
- HDU 5531 Rebuild(三分)——2015ACM/ICPC亚洲区长春站
- 2015ACM/ICPC亚洲区长春站 HDU 5532
- HDU 5533 Dancing Stars on Me——几何
- HDU 5538 House Building(矩阵处理 表面积 水)——2015ACM/ICPC亚洲区长春站
- 2015ACM/ICPC亚洲区长春站————House Building
- hdu 5533 Dancing Stars on Me
- hdu 5533 Dancing Stars on Me
- PAT 1019. General Palindromic Number (20)
- python正则表达式
- python 随机产生多维高斯分布点
- hdu3646 Fate Stay Night(dp,读题障碍)
- Notification_安卓
- HDU 5533 Dancing Stars on Me(判断n个整数点是否能组成正n边形)——2015ACM/ICPC亚洲区长春站
- Longest Common Prefix
- HDOJ 1995 汉诺塔V
- 粒子群算法的matlab实现
- 【程序44】 题目:一个偶数总能表示为两个素数之和。
- 拼图小游戏“ST--拼图”开发篇之主要功能的实现(三)
- AlertDialog的初步了解
- 新手必看之UILabel
- Codeforces Round #328 (Div. 2)