8.全排列[深度优先搜索]

/*-----深度优先搜索----全排列--------*/

#include <iostream>
using namespace std;
int a[10],book[10],n;
void dfs(int step)/*step第几个盒子*/
{
    int i;
    if(step==n+1)
    {
        for(i=1;i<=n;i++)
            cout<<a[i]<<" ";
        cout<<endl;
        return;
    }
    for(i=1;i<=n;i++)
    {
        if(book[i]==0)
        {
            a[step]=i;
            book[i]=1;
            dfs(step+1);
            book[i]=0;
        }
    }
    return ;
}

int main()
{
    cin>>n;
    dfs(1);
    return 0;
}