Submission #11377385

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Source Code Expand

#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<complex>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<tuple>
using namespace std;
typedef long long ll;
typedef unsigned int ui;
const ll mod = 1000000007;
const ll INF = (ll)1000000007 * 1000000007;
typedef pair<int, int> P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define Per(i,sta,n) for(int i=n-1;i>=sta;i--)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
typedef long double ld;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<ll, ll> LP;
int dx[4]={1,-1,0,0};
int dy[4]={0,0,1,-1};

int n,max_x;
ld dp[(1 << 20)];

ld get_dp(int S){
    //cout << bitset<10>(S) << endl;
    if(S==0) return 0;
    if(dp[S]!=-1) return dp[S];
    ld res=0;
    int nex1=0,nex2=0;
    int s;
    rep(i,max_x){
        if(S&(1 << i)){
            s=i;
            if(S&(1 << (i+1))) nex1=1;
            if(S&(1 << (i+2))) nex2=1;
            break;
        }
    }
    if(nex1==1 && nex2==1){
        res+=get_dp(S^(1 << s))/3;
        res+=get_dp(S^(1 << (s+1)))/3;
        res+=get_dp(S^(1 << (s+2)))/3;
        res-=1;
    }
    if(nex1==1 && nex2==0){
        res+=get_dp(S^(1 << s))/2;
        res+=get_dp(S^(1 << (s+1)))/2;
        res-=1.5;
    }
    if(nex1==0 && nex2==1){
        res+=get_dp(S^(1 << s))/2;
        res+=get_dp(S^(1 << (s+2)))/2;
        res-=1.5;
    }
    if(nex1==0 && nex2==0){
        res+=get_dp(S^(1 << s));
        res-=3;
    }
    dp[S]=res;
    //cout << bitset<10>(S) << " " << dp[S] << endl;
    return res;
}

void solve(){
    cin >> n;
    int T=0;
    rep(i,n){
        int x;cin >> x;
        max_x=max(max_x,x);
        T+=(1 << x);
    }
    rep(i,(1 << 19)){
        dp[i]=-1;
    }
    cout << -get_dp(T) << endl;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(50);
    solve();
}

Submission Info

Judge Result