[DFS] [洛谷] P1706 全排列问题

私以为此乃DFS之基础

即DFS均以此拓展而来

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

const int MAXN = 1e5 + 10;

int N;

bool used[MAXN] = {0};

int arr[MAXN] = {0};

void dfs(int rit, int num)
{
    if(num == N)
    {
        for(int i = 0; i < N; i++)
        {
            printf("%5d",arr[i]);
        }
        cout<<endl;
    }
    
    for(int i = 1; i <= N; i++)
    {
        if(!used[i])
        {
            used[i] = true;

            arr[num] = i; 
            
            dfs(i, num + 1);
            
            used[i] = false;
        }
        
    }
}

int main()
{
    cin>>N;

    dfs(0, 0);

    return 0;
}