The 36th ACM/ICPC Asia Regional Chengdu Site 1003 Regular Polygon
2011-09-13 20:54
260 查看
比赛时悲剧的没做出来,赛后终于解决了,革命尚未成功,同志仍需努力呀!
#include <iostream> #include <math.h> #include <stdio.h> using namespace std; const int N=102; double pi=acos(-1); const double eps=1e-8; double dis ; int n; double solve (double l,double r) { if(fabs(l-r)<eps)return -1; double mid=(l+r)/2; int i; double ang=0; for(i=0;i<n;i++) { if(mid-(dis[i]+dis[i+1])>eps)return solve(l,mid);//边太大,构不成三角形 if(mid-fabs(dis[i]-dis[i+1])<eps)return solve(mid,r);//边太小,构不成三角形 double cs=(dis[i]*dis[i]+dis[i+1]*dis[i+1]-mid*mid)/(2*dis[i]*dis[i+1]); ang+=acos(cs); } if(fabs(ang-2*pi)<eps)return mid;//等于360度 else if(ang-2*pi>eps)return solve(l,mid);//大于360度,说明mid太大 else return solve(mid,r);//小于360度说明mid太小 return -1; } int main() { int t; cin>>t; int ca=1; while(t--) { cin>>n; int i; for(i=0;i<n;i++) { scanf("%lf",&dis[i]); } dis =dis[0]; double ans=solve (0,20000); if(ans==-1)printf("Case %d: impossible\n",ca); else printf("Case %d: %.3lf\n",ca,ans); ca++; } return 0; } /* 2 3 3.0 4.0 5.0 3 1.0 2.0 3.0 */
相关文章推荐
- The 36th ACM/ICPC Asia Regional Dalian Site 1003 The Frog's Games
- hdu 4750 Count The Pairs 并查集+递推(2013 ACM/ICPC Asia Regional Nanjing Online 1003)
- 2016 Multi-University Training Contest 5 1003 Divide the Sequence (贪心)
- 2017 ACM-ICPC 亚洲区(青岛赛区)网络赛 HDU 6208 1003 The Dominator of Strings(AC自动机)
- The 36th ACM/ICPC Asia Regional Beijing Site Online Contest - G Panda
- DP BestCoder Round #50 (div.2) 1003 The mook jong
- 4046 Panda(The 36th ACM/ICPC Asia Regional Beijing Site —— Online Contest)
- 17ACM Qingdao 1003 The Dominator of Strings
- 2011成都网赛 / 1003 - Regular Polygon
- 2015‘12杭电校赛1003 The collector’s puzzle(双指针水题)
- The 36th ACM/ICPC Asia Regional Beijing Site Online Contest - B Eliminate Witches!
- The 36th ACM/ICPC Asia Regional Dalian Site —— Online Contest(套题HDU4001-4010)
- hdu 4750 Count The Pairs 并查集+递推(2013 ACM/ICPC Asia Regional Nanjing Online 1003)
- 2011成都网赛 / 1003 - Regular Polygon
- 2016 Multi-University Training Contest 5 1003 Divide the Sequence
- HDU 4031 Attack(离线+线段树)(The 36th ACM/ICPC Asia Regional Chengdu Site —— Online Contest)
- 4045 Machine scheduling(The 36th ACM/ICPC Asia Regional Beijing Site —— Online Contest)
- The 36th ACM/ICPC Asia Regional Shanghai Site —— Warmup
- 多校第三场 1003 5318 The Goddess Of The Moon(dp+矩阵快速幂)
- HDU 4750 Count The Pairs (2013南京网络赛1003题,并查集)