UVa 291 - The House Of Santa Claus Solution

#include<iostream>
#include<list>
#include<string>
#include<cstring>
#include<sstream>
#include<cctype>
#include<string.h>
#include<algorithm>
#include<cmath>
#include<stack>
#include<fstream>
#include<cstdlib>
#include<vector>
#include<map>
#include<set>
#include<utility>
#include<iomanip>
#include<queue>

using namespace std;

#define INF (1<<29)
#define SET(a) memset(a,-1,sizeof(a))
#define ALL(a) a.begin(),a.end()
#define CLR(a) memset(a,0,sizeof(a))
#define FILL(a,v) memset(a,v,sizeof(a))
#define PB push_back
#define FOR(i,n) for(int i = 0;i<n;i++)
#define PI acos(-1.0)
#define EPS 1e-9
#define MP(a,b) make_pair(a,b)
#define min3(a,b,c) min(a,min(b,c))
#define max3(a,b,c) max(a,max(b,c))
#define READ(f) freopen(f, "r", stdin)
#define WRITE(f) freopen(f, "w", stdout)
#define LL long long
#define MX 100000
#define MOD 1000000007

int edge[10][10],u1[]={2,3,5},u2[]={1,3,5},u3[]={1,2,4,5},u4[]={3,5},u5[]={1,2,3,4};

void drawing(int stk, int n)
{
    int i;
    if(n==8)
    {
        cout<<stk<<endl;
        return;
    }
    int prev=stk%10;

    if(prev==1)
    {
        for(i=0;i<3;i++)
            if(!edge[prev][u1[i]])
            {
                edge[prev][u1[i]]=1;
                edge[u1[i]][prev]=1;
                drawing(stk*10+u1[i], n+1);
                edge[prev][u1[i]]=0;
                edge[u1[i]][prev]=0;
            }
    }

    else if(prev==2)
    {
        for(i=0;i<3;i++)
            if(!edge[prev][u2[i]])
            {
                edge[prev][u2[i]]=1;
                edge[u2[i]][prev]=1;
                drawing(stk*10+u2[i], n+1);
                edge[prev][u2[i]]=0;
                edge[u2[i]][prev]=0;
            }
    }

    else if(prev==3)
    {
        for(i=0;i<4;i++)
            if(!edge[prev][u3[i]])
            {
                edge[prev][u3[i]]=1;
                edge[u3[i]][prev]=1;
                drawing(stk*10+u3[i], n+1);
                edge[prev][u3[i]]=0;
                edge[u3[i]][prev]=0;
            }
    }

    else if(prev==4)
    {
        for(i=0;i<2;i++)
            if(!edge[prev][u4[i]])
            {
                edge[prev][u4[i]]=1;
                edge[u4[i]][prev]=1;
                drawing(stk*10+u4[i], n+1);
                edge[prev][u4[i]]=0;
                edge[u4[i]][prev]=0;
            }
    }

    else if(prev==5)
    {
        for(i=0;i<4;i++)
            if(!edge[prev][u5[i]])
            {
                edge[prev][u5[i]]=1;
                edge[u5[i]][prev]=1;
                drawing(stk*10+u5[i], n+1);
                edge[prev][u5[i]]=0;
                edge[u5[i]][prev]=0;
            }
    }
}


int main()
{
drawing(1,0);
return 0;
}