CodeForce977D - Divide by three, multiply by two(深度优先搜索)

Polycarp likes to play with numbers. He takes some integer number xx, writes it down on the board, and then performs with it n−1n−1 operations of the two kinds:

  • divide the number xx by 33 (xx must be divisible by 33);
  • multiply the number xx by 22.

After each operation, Polycarp writes down the result on the board and replaces xx by the result. So there will be nn numbers on the board after all.

You are given a sequence of length nn — the numbers that Polycarp wrote down. This sequence is given in arbitrary order, i.e. the order of the sequence can mismatch the order of the numbers written on the board.

Your problem is to rearrange (reorder) elements of this sequence in such a way that it can match possible Polycarp's game in the order of the numbers written on the board. I.e. each next number will be exactly two times of the previous number or exactly one third of previous number.

It is guaranteed that the answer exists.

Input

The first line of the input contatins an integer number nn (2≤n≤1002≤n≤100) — the number of the elements in the sequence. The second line of the input contains nn integer numbers a1,a2,…,ana1,a2,…,an (1≤ai≤3⋅10181≤ai≤3⋅1018) — rearranged (reordered) sequence that Polycarp can wrote down on the board.

Output

Print nn integer numbers — rearranged (reordered) input sequence that can be the sequence that Polycarp could write down on the board.

It is guaranteed that the answer exists.

Examples

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input

Copy

6
4 8 6 3 12 9

output

Copy

9 3 6 12 4 8 

input

Copy

4
42 28 84 126

output

Copy

126 42 84 28 
#include <cstdio>
#include<iostream>
#include <cstring>
#include <iostream>
#include <cmath>
#define ll long long
using  namespace std;
ll n,a[100+10],num[100+10];
bool mark[100+10];
void dfs(int step,int num1)
{
    if(step==n+1)//递归终止条件;
    {
        for(int i=1;i<=n;i++)
            cout<<num[i]<<" ";
        return ;
    }
    ll temp=a[num1];
    for(int i=1;i<=n;i++)
    {
        if(temp%3==0&&temp/3==a[i]&&!mark[i])
        {
            mark[i]=true;
            num[step]=a[i];
            dfs(step+1,i);
            mark[i]=false;
        }
        else if(temp*2==a[i]&&!mark[i])
        {
            mark[i]=true;
            num[step]=a[i];
            dfs(step+1,i);
            mark[i]=false;
        }
    }
}
int main()
{
    cin>>n;
    for(ll i=1;i<=n;i++)
    {
        cin>>a[i];
    }
    for(ll i=1;i<=n;i++)
    {
        memset(mark,false,sizeof(mark));
        num[1]=a[i];
        mark[i]=true;
        dfs(2,i);
    }
}


#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<string>
#include<cstdlib>
#include<queue>
#include<set>
#include<map>
#include<stack>
#include<ctime>
#include<vector>
#define INF 0x3f3f3f3f
#define PI acos(-1.0)
#define N 1005
#define MOD 1e9+7
#define E 1e-6
typedef long long ll;
using namespace std;
int n;
ll a[N],num[N];
int vis[N];
int cnt;
void dfs(int step,int now)
{
    ll temp=a[now];
 
    if(step==n)
    {
        for(int i=0;i<cnt;i++)
            cout<<num[i]<<" ";
        cout<<endl;
        return;
    }
 
    for(int i=1;i<=n;i++)
    {
        if( (temp/3==a[i]) && (temp%3==0) )
        {
            if(!vis[i])
            {
                vis[i]=1;
                num[cnt]=a[i];
                cnt++;
 
                dfs(step+1,i);
 
                vis[i]=0;
                cnt--;
            }
        }
 
        if(temp*2==a[i])
        {
            if(!vis[i])
            {
                vis[i]=1;
                num[cnt]=a[i];
                cnt++;
                dfs(step+1,i);
 
                vis[i]=0;
                cnt--;
            }
        }
    }
}
int main()
{
    cin>>n;
    for(int i=1;i<=n;i++)
        cin>>a[i];
 
    for(int i=1;i<=n;i++)
    {
        cnt=1;
        num[0]=a[i];
        memset(vis,0,sizeof(vis));
 
        dfs(1,i);
    }
 
    return 0;
}

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转载自blog.csdn.net/lanshan1111/article/details/81570245