Submission #968590

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Source Code Expand

#include<cstdio>
#include<iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<queue>
#include<stack>
#include<map>
#include<math.h>
#include<iomanip>

#define rep0(i,N) for(int i=0;i<N;i++)
#define rep1(i,a,N) for(int i=0+a;i<N;i++)
#define lint long long int
#define SIZE 100005
#define INF 1000000000


using namespace std;

int main(){
	bool use[100005];
	long long int r,n,m;
	cin>>r>>n>>m;
	n=n-1;
	double num[200000]={};
	double cc,ans=0;
	double rest;
	rep0(i,n)use[i]=false;
	rep0(i,n){
		if(n%2==1){
			double r1=r,n1=n;
			rest=(2*r1)/(n1+1);
			cc=(n-1)/2;
		}
		else{
			double r1=r,n1=n;
			rest=(2*r1)/(n1+1);
			cc=n/2-0.5;
		}
		num[i]=sqrt(r*r-pow((abs(cc-i)*rest),2))*4;
	}
	rep0(i,n){
		if(use[i]==false){
		use[i]=true;
		use[i+m]=true;
		ans+=max(num[i],num[i+m]);
		}
	}
	cout<< fixed << setprecision(8) <<ans; 

return 0;
}

Submission Info

Judge Result