Submission #1766534

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Source Code Expand

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<ctime>
#include<cctype>
#include<climits>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<memory>
#include<functional>
#include<set>
 
using namespace std;
 
#define ALL(g) (g).begin(),(g).end()
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)
#define P(p) cout<<(p)<<endl;
#define p(p) cout<<(p)<<" ";
#define pb push_back
#define mp make_pair
#define INF 1<<25

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int, int> pi;
typedef long long ll;

int dy[8]={1,1,1,0,0,-1,-1,-1};
int dx[8]={-1,0,1,-1,1,-1,0,1};
struct S{
	int a,b,c;
};
bool asc(const S& left,const S& right){
	return left.c > right.c;
}

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	int N;
	cin>>N;
	vector<int>C(N);
	rep(i,N)cin>>C[i];
	double ans=0;
	rep(i,N){
		int cnt=0;
		rep(j,N){
			if(i==j)continue;
			if(C[i]%C[j]==0){
				cnt++;
			}
		}

		if(cnt%2==1)ans+=0.5;
		else ans+=(double)(cnt+2)/(2*cnt+2);

	}
	printf("%.10f\n",ans);
	return 0;
}

Submission Info

Judge Result