HDU5533 Dancing Stars on Me(计算几何)
来源:互联网 发布:中国云计算大会 2017 编辑:程序博客网 时间:2024/06/05 02:44
Dancing Stars on Me
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 1800 Accepted Submission(s): 1045
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颗星星的坐标求星星是否能构成正n边形
思路:因为是n个星星就要正n边形,而且给你的点的坐标都是整数,所以只有当n为4时才可能构成正n边形,即正方形,其他形状时必有两边不相等而不得其他边形,所以当n为4时将两两个点的距离计算出来然后排个序,若为正方形,则四边相等对角线相等
#include <iostream>#include <cstdio>#include <cstring>#include <stdio.h>#include <stdlib.h>#include <algorithm>#include <math.h>using namespace std;struct point{ double x,y;};double dis(point a,point b){ return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));}int main(){ int t; scanf("%d",&t); while(t--) { int n; scanf("%d",&n); point a[n]; for(int i=0;i<n;i++) scanf("%lf%lf",&a[i].x,&a[i].y); if(n!=4) { printf("NO\n"); continue; } double b[6]; b[0]=dis(a[0],a[1]); b[1]=dis(a[1],a[2]); b[2]=dis(a[2],a[3]); b[3]=dis(a[0],a[2]); b[4]=dis(a[0],a[3]); b[5]=dis(a[1],a[3]); sort(b,b+6); if(b[0]==b[1]&&b[1]==b[2]&&b[2]==b[3]&&b[4]==b[5]) printf("YES\n"); else printf("NO\n"); } return 0;}
阅读全文
0 0
- HDU5533 Dancing Stars on Me(计算几何)
- HDU5533 Dancing Stars on Me(计算几何)
- hdu5533 Dancing Stars on Me(几何水)
- HDU5533 Dancing Stars on Me
- HDU5533 Dancing Stars on Me 数学 国庆咸鱼
- hdu 5533 Dancing Stars on Me【计算几何】
- HDU 5533 Dancing Stars on Me 计算几何瞎暴力
- 巧妙地计算几何 Dancing Stars on Me
- HDU5533 Dancing Stars on Me(极角排序+判断正n边形)
- 【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 (2015ACM/ICPC亚洲区长春 &&计算几何)
- [hdu 5533][2015ACM/ICPC亚洲区长春站] Dancing Stars on Me 计算几何
- hdoj Dancing Stars on Me 5533 (数学几何&&技巧)
- HDU-5533 Dancing Stars on Me(几何/极点排序)
- HDU 5533 Dancing Stars on Me——几何
- hdu5533Dancing Stars on Me(简单计算几何)
- HDU5533Dancing Stars on Me(计算几何)
- HDU Dancing Stars on Me
- 日常学习2017.8.5
- GDOI训练 暑假round 2 8.5-8.25
- BZOJ 2049: [Sdoi2008]Cave 洞穴勘测 link cut tree
- poj 2227 The Wedding Juicer
- idea can't resolve the symbol "servlet"
- HDU5533 Dancing Stars on Me(计算几何)
- ReactNative之弹出窗
- Codeforces
- 定宽高的水平垂直居中
- RedisTemlale操作List测试类
- js SyntaxError: unterminated string literal
- UESTC
- Android Https相关完全解析 当OkHttp遇到Https
- CocoaPods管理三方开源库