Submission #409012


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#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <map>
#include <set>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <sstream>
#include <complex>
#include <stack>
#include <queue>
#include <cstdio>
#include <cstring>
#include <iterator>
#include <bitset>
#include <unordered_set>
#include <unordered_map>
//#include <utility>
//#include <memory>
//#include <functional>
//#include <deque>
//#include <cctype>
//#include <ctime>
//#include <numeric>
//#include <list>
//#include <iomanip>

//#if __cplusplus >= 201103L
//#include <array>
//#include <tuple>
//#include <initializer_list>
//#include <forward_list>
//
//#define cauto const auto&
//#else

//#endif

using namespace std;


typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef vector<int> vint;
typedef vector<vector<int> > vvint;
typedef vector<long long> vll, vLL;
typedef vector<vector<long long> > vvll, vvLL;

#define VV(T) vector<vector< T > >

template <class T>
void initvv(vector<vector<T> > &v, int a, int b, const T &t = T()){
    v.assign(a, vector<T>(b, t));
}

template <class F, class T>
void convert(const F &f, T &t){
    stringstream ss;
    ss << f;
    ss >> t;
}


#define reep(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n) reep((i),0,(n))
#define ALL(v) (v).begin(),(v).end()
#define PB push_back
#define F first
#define S second
#define mkp make_pair
#define RALL(v) (v).rbegin(),(v).rend()
#define DEBUG
#ifdef DEBUG
#define dump(x)  cout << #x << " = " << (x) << endl;
#define debug(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
#else
#define dump(x) 
#define debug(x) 
#endif

#define MOD 1000000007LL
#define EPS 1e-8
static const int INF=1<<24;

void mainmain(){
    int n;
    cin>>n;
    vint v(n);
    rep(i,n) cin>>v[i];
    sort(ALL(v));
    vint w(n,0);
    rep(i,n){
        rep(j,n){
            if(i==j) continue;
            if(v[i]%v[j]==0) w[i]++;
        }
    }
    vector<double> a(n+10);
    a[0]=a[1]=1.0;
    reep(i,2,n+10){
        a[i]=a[i-1]*i;
    }
    double c[110][110];
    rep(i,110) rep(j,110) c[i][j]=0.0;
    c[0][0]=c[1][0]=c[1][1]=1.0;
    rep(i,110){
        c[i][0]=1.0;
        reep(j,1,i+1){
            c[i][j]=c[i-1][j]+c[i-1][j-1];
        }
    }
    // cout<<n<<endl;
    double ans=0.0;
    rep(i,n){
        rep(j,n){
            // if(j==0) ans+=a[n-1];
            rep(l,w[i]+1){
                if(l&1) continue;
                if(j<l) continue;
                if(j-l>n-1-w[i]) continue;
                int t1=j-l;
                int t2=n-j-1;
                // cout<<i<<" "<<j<<" "<<l<<" "<<c[w[i]][l]*c[j][l]*a[l]<<" "<<c[n-1-w[i]][j-l]*a[j-l]<<" "<<a[n-1-j]<<endl;
                ans+=c[w[i]][l]*c[j][l]*a[l]*c[n-1-w[i]][j-l]*a[j-l]*a[n-1-j];
            }
        }
    }
    // cout<<a[n]<<endl;
    // cout<<ans/a[n]<<endl;
    printf("%.8lf\n",ans/a[n]);
}


signed main() {
    mainmain();
}

Submission Info

Submission Time
Task C - コイン
User j_gui0121
Language C++11 (GCC 4.8.1)
Score 100
Code Size 3125 Byte
Status AC
Exec Time 29 ms
Memory 932 KB

Judge Result

Set Name Sample Subtask1 Subtask2
Score / Max Score 0 / 0 99 / 99 1 / 1
Status
AC × 3
AC × 20
AC × 40
Set Name Test Cases
Sample sample_01.txt, sample_02.txt, sample_03.txt
Subtask1 subtask1_01.txt, subtask1_02.txt, subtask1_03.txt, subtask1_04.txt, subtask1_05.txt, subtask1_06.txt, subtask1_07.txt, subtask1_08.txt, subtask1_09.txt, subtask1_10.txt, subtask1_11.txt, subtask1_12.txt, subtask1_13.txt, subtask1_14.txt, subtask1_15.txt, subtask1_16.txt, subtask1_17.txt, subtask1_18.txt, subtask1_19.txt, subtask1_20.txt
Subtask2 subtask1_01.txt, subtask1_02.txt, subtask1_03.txt, subtask1_04.txt, subtask1_05.txt, subtask1_06.txt, subtask1_07.txt, subtask1_08.txt, subtask1_09.txt, subtask1_10.txt, subtask1_11.txt, subtask1_12.txt, subtask1_13.txt, subtask1_14.txt, subtask1_15.txt, subtask1_16.txt, subtask1_17.txt, subtask1_18.txt, subtask1_19.txt, subtask1_20.txt, subtask2_01.txt, subtask2_02.txt, subtask2_03.txt, subtask2_04.txt, subtask2_05.txt, subtask2_06.txt, subtask2_07.txt, subtask2_08.txt, subtask2_09.txt, subtask2_10.txt, subtask2_11.txt, subtask2_12.txt, subtask2_13.txt, subtask2_14.txt, subtask2_15.txt, subtask2_16.txt, subtask2_17.txt, subtask2_18.txt, subtask2_19.txt, subtask2_20.txt
Case Name Status Exec Time Memory
sample_01.txt AC 24 ms 924 KB
sample_02.txt AC 23 ms 808 KB
sample_03.txt AC 23 ms 928 KB
subtask1_01.txt AC 23 ms 800 KB
subtask1_02.txt AC 25 ms 840 KB
subtask1_03.txt AC 24 ms 796 KB
subtask1_04.txt AC 23 ms 800 KB
subtask1_05.txt AC 23 ms 804 KB
subtask1_06.txt AC 24 ms 932 KB
subtask1_07.txt AC 23 ms 792 KB
subtask1_08.txt AC 24 ms 928 KB
subtask1_09.txt AC 23 ms 928 KB
subtask1_10.txt AC 23 ms 928 KB
subtask1_11.txt AC 24 ms 932 KB
subtask1_12.txt AC 24 ms 800 KB
subtask1_13.txt AC 24 ms 924 KB
subtask1_14.txt AC 24 ms 924 KB
subtask1_15.txt AC 24 ms 844 KB
subtask1_16.txt AC 24 ms 924 KB
subtask1_17.txt AC 24 ms 796 KB
subtask1_18.txt AC 27 ms 772 KB
subtask1_19.txt AC 24 ms 932 KB
subtask1_20.txt AC 24 ms 804 KB
subtask2_01.txt AC 24 ms 920 KB
subtask2_02.txt AC 23 ms 924 KB
subtask2_03.txt AC 24 ms 796 KB
subtask2_04.txt AC 27 ms 924 KB
subtask2_05.txt AC 25 ms 864 KB
subtask2_06.txt AC 24 ms 796 KB
subtask2_07.txt AC 23 ms 800 KB
subtask2_08.txt AC 26 ms 928 KB
subtask2_09.txt AC 27 ms 924 KB
subtask2_10.txt AC 27 ms 928 KB
subtask2_11.txt AC 24 ms 796 KB
subtask2_12.txt AC 26 ms 920 KB
subtask2_13.txt AC 23 ms 924 KB
subtask2_14.txt AC 26 ms 924 KB
subtask2_15.txt AC 25 ms 844 KB
subtask2_16.txt AC 26 ms 800 KB
subtask2_17.txt AC 25 ms 924 KB
subtask2_18.txt AC 24 ms 928 KB
subtask2_19.txt AC 24 ms 924 KB
subtask2_20.txt AC 29 ms 908 KB