제출 #479847

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
479847		hjc4vr	아름다운 순열 (IZhO12_beauty)	C++14	0 / 100	8 ms	1612 KiB

beauty

#include <bits/stdc++.h>
//#define int long long
using namespace std;
int const maxn = 2005,MOD=1e9 + 7;
int d[maxn];
struct road{
    int a,b,cost;
};

int pow(int a,int b){
    int result = 1;
    while (b>0){
        if (b&1) {
            result *= a;
        }
        a = a*a;
        b = b>>1;
    }
    return result;
}
int gcd(int a,int b){
    if (b==0) return a;
    if (a<b) swap(a,b);
    return gcd(b,a%b);
}
int count2(int x){
    return __builtin_popcount(x);
}
int count3(int x){
    int cnt=0;
    while (x){
        if (x%3==1) cnt++;
        x/=3;
    }
    return cnt;
}
int dp[1<<20][21];
void solve(){
    int n;cin>>n;
    int arr[n+1];
    for (int i=1;i<=n;++i) cin >> arr[i];
    pair<int,int> v[n+1];
    for (int i=1;i<=n;++i) v[i] = make_pair(count2(arr[i]),count3(arr[i]));
    for (int mask=1;mask<(1<<n);++mask){
        int sz=0;
        int last=0;
        for (int i=0;i<n;++i) if ((1<<i)&mask) sz++, last = i;
        if (sz==1) dp[mask][last] = 1;
        else{
            for (int i=0;i<n;++i){
                if ((1<<i)&mask){
                    int next_mask = (1<<i)^mask;
                    for (int j=0;j<n;++j){
                        if ((1<<j)&next_mask and (v[j+1].first==v[i+1].first or v[j+1].second==v[i+1].second)){
                            dp[mask][i] += dp[next_mask][j];
                        }
                    }
                }
            }
        }
    }
    int ans =0;
    for (int i=0;i<n;++i) ans += dp[(1<<n)-1][i];
    cout << ans;
}
int32_t main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    solve();
}
   
//
//4
//4
//2
//2
//2
//4
//4
//4
//4
//2
//4
//4
//2

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