Firetruck UVA - 208

#include<bits/stdc++.h>
using namespace std;
int E[30][30];
int diste;
int mark[30];
int path[30];
int fin[30];
int ans;
int root[30];
void init()  
{  
    for(int i=1;i<=21;i++)  
        root[i] = i;  
}  
int find(int p)  
{  
    int t;  
    int child = p;  
    while(p != root[p])  
        p = root[p];  
    while(child != p)  
    {  
        t = root[child];  
        root[child] = p;  
        child = t;  
    }  
    return p;  
}  
void merge(int x, int y)  
{  
    int fx = find(x);  
    int fy = find(y);  
    if(fx != fy)  
        root[fx] = fy;  
}  
void input()
{
    memset(E,0,sizeof E);
    int a,b;
    while(scanf("%d%d",&a,&b)&&a&&b)
    {
        E[a][b]=1;
        E[b][a]=1;  
        merge(a,b);
    }
}
void print(int g)
{
    int q=path[g];
    int len=0;
    fin[len++]=g;
    while(q!=0)
    {
        fin[len++]=q;
        q=path[q];
    }
    while(len--)
    printf("%d%c",fin[len],len==0?‘\n‘:‘ ‘);
}

void DFS(int g)
{    
    if(g==diste)
    {
        print(g);
        ans++;
        return;
    }
    mark[g]=1;
    
    for(int a=1;a<=21;a++)
    {
        if(E[a][g]&&!mark[a]&&find(a)==find(diste))
        {
        path[a]=g;
        DFS(a);    
        }
        
    }
    mark[g]=0;
    
}

int main()
{
    int t=0;
    while(scanf("%d",&diste)!=EOF)
    {
        ans=0;
        t++;
        init();
        input();
        
        printf("CASE %d:\n",t);
    //    for(int i=1;i<=diste;i++)
    //    cout<<i<<":"<<root[i]<<endl;
        DFS(1);
        printf("There are %d routes from the firestation to streetcorner %d.\n",ans,diste);
    }
    return 0;
}