题目描述

blablabla

样例

blablabla

blablabla

时间复杂度分析：blablabla

C++ 代码

#include<iostream>
#include<vector>
using namespace std;

const int N = 10000;
int n, p[N];
//vector<int> p;
bool s[N];

void dfs(int u, int state)
{
    if(u == n)
    {   for(int i = 0; i < n; i++)
            cout << p[i] << " ";
        cout << endl;
    }
    else
    {
        for(int i = 1; i <= n; i++)
            if( !(state >> i & 1))  //第i位没有被选中
            {
                p[u] = i; 
                dfs(u+1, 1 << i | state); //把第i位标记为选中
            }
    }
}
int main()
{
    cin >> n;
    dfs(0, 0);
    return 0;
}

#include<iostream>
using namespace std;

const int N = 10000;
int n, p[N];
bool s[N];

void dfs(int u)
{
    if(u == n)
    {   for(int i = 0; i < n; i++)
            cout << p[i] << " ";
        cout << endl;
    }
    else
    {
        for(int i = 1; i <= n; i++)
            if( !s[i])
            {
                p[u] = i; s[i] = true;
                dfs(u+1 ); s[i] = false;
            }
    }
}
int main()
{
    cin >> n;
    dfs(0);
    return 0;
}