DFS 10.1.5.253 1501

#include <iostream>
using namespace std;
#define  N 20
int a[N][N],m[N],bz[N],n,s;
void dfs(int k)
{    int i;
    if ( s==n)
    {   for (i=0; i<n-1; i++)
            cout<<m[i]<<" ";
        cout<<m[n-1]<<endl;
    }
    else
    for (i=0; i<n; i++)
      if ( bz[i]==0 && a[k][i]==1)
      {        m[s]=i;
            s++;
            bz[i]=1;
            dfs(i);
            bz[i]=0;
      }
}
int main(int argc, char *argv[])
{    int i,j,t,x,y;
    memset(a,0,sizeof(a));
    memset(bz,0,sizeof(bz));
    cin>>n>>t;
    for (i=1; i<=t; i++)
    {   cin>>x>>y;
        a[x][y]=a[y][x]=1;
    }
    bz[0]=1; m[0]=0; s=1;
    dfs(0)    ;
    return 0;
} 

****************************************************************************************

#include<iostream>
#include<queue>
#include<vector>
#include<algorithm>
#include<cmath>
#include<map>
#include<stdio.h>
#include<cstring>

//#define DEBUG

using namespace std;

vector<int>ve[1005];
int d[1005],flag;

void DFS(int k)
{
    if(flag==0){  cout<<k; flag=1; }
    else cout<<" "<<k;
    d[k]=1;
    for(int i=0;i<ve[k].size();++i)
    {
        if(d[ve[k][i]]==0)DFS(ve[k][i]);
    }
}

int main()
{
    //#ifndef ONLINE_JUDGE
    #ifdef DEBUG
    freopen("in.txt","r",stdin);
    #endif
    int n,m,a,b;
    while(cin>>n>>m)
    {
        for(int i=0;i<n;++i)ve[i].clear();
        for(int i=0;i<m;++i)
        {
            cin>>a>>b;
            ve[a].push_back(b);
            ve[b].push_back(a);
        }
        for(int i=0;i<n;++i)sort(ve[i].begin(),ve[i].end());
        flag=0;
        memset(d,0,sizeof(d));
        DFS(0);
    }
    //#ifndef ONLINE_JUDGE
    #ifdef DEBUG
    freopen("con","r",stdin);
    system("pause");
    #endif
    return 0;

}

************************************************************************************8

#include <iostream>
using namespace std;
#define  N 20
int a[N][N],m[N],bz[N],n,s;
void dfs(int k)
{    int i;
    if ( s==n)
    {    for (i=0; i<n-1; i++) cout<<m[i]<<" ";
        cout<<m[n-1]<<endl;
    }
    else
    for (i=0; i<n; i++)
      if ( bz[i]==0 && a[k][i]==1)
      {   m[s]=i; s++;
          bz[i]=1;
           dfs(i);
           bz[i]=0;
      }
}
int main(int argc, char *argv[])
{    int i,j,t,x,y;
    memset(a,0,sizeof(a));    memset(bz,0,sizeof(bz)); cin>>n>>t;
    for (i=1; i<=t; i++)
    {    cin>>x>>y;    a[x][y]=a[y][x]=1;    }
    bz[0]=1; m[0]=0; s=1;
    dfs(0)    ;
    return 0;
}