336 - A Node Too Far

/*
  Problem Id : 336 - A Node Too Far
  Author     : Kaidul Islam
               Khulna University of Engr. & Tech.
*/
#include<iostream>
#include<algorithm>
#include<vector>
#include<cstring>
#include<queue>
#include<stack>
#include<set>
#include <fstream>

#define Max 100000
#define pb push_back
#define READ(f) freopen(f, "r", stdin)
#define WRITE(f) freopen(f, "w", stdout)
using namespace std;

vector<int>adj[Max];
int main()
{
    //READ("in.txt");
    queue<int>q;
    set<int>s;
    int caseNo=1,e,x,y,src,ttl;
    int dis[Max+1],visited[Max];
    memset(visited, 0,sizeof(visited));
    label:
    while(cin>>e)
    {
        for(int i=0;i<Max;i++) adj[i].clear();
        q=queue<int>();
        s.clear();
        if(e==0) return 0;
        else
        {
            for(int i=0;i<e;i++)
            {
              cin>>x>>y;
              adj[x].pb(y);
              adj[y].pb(x);
              s.insert(x);
              s.insert(y);

            }
            while(cin>>src>>ttl)
            {
                if(src==0 && ttl==0) goto label;
                else
                {
                    int count=1,z=0;
                    q.push(src);
                    dis[src]=0;
                    visited[src]=1;
                    while(!q.empty())
                    {
                        int pop=q.front();
                        for(int i=0;i<(int)adj[pop].size();i++)
                        {
                            int temp=adj[pop][i];
                            if(!visited[temp])
                            {
                                dis[temp]=dis[pop]+1;
                                if(dis[temp]>ttl) break;
                                q.push(temp);
                                visited[temp]=1;
                                count++;
                            }
                        }
                        q.pop();
                    }
                    z=s.size()-count;
                    if( z<0 ) z=0;
                    cout<<"Case "<<caseNo<<": "<<z
                        <<" nodes not reachable from node "
                        <<src<<" with TTL = "<<ttl<<".\n";
                    caseNo++;
                 }
                 memset(visited, 0, sizeof(visited));
            }
        }
    }
    return 0;
}