A node too far

#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#include <set>

using namespace std;

int main()
{
    long long NC, i, j, k, u, v, nodes, maxi, reach, kase = 1, ttl, lev;
    vector<long long> graph[100100];
    set<long long> s;
    while((scanf("%lld", &NC) == 1) && NC){
        maxi = 0;
        for(i = 0; i < NC; i++){
            scanf("%lld %lld", &u, &v);
            graph[u].push_back(v);
            graph[v].push_back(u);
            if(maxi < max(u, v))maxi = max(u, v);
            s.insert(u);
            s.insert(v);
            //printf("%d\n", s.size());
        }
        nodes = s.size();

        while(scanf("%lld %lld", &u, &v) == 2){
            if(u == 0 && v == 0)break;

            ttl = v;
            queue<int>Q[35];
            lev = 0;
            Q[lev].push(u);
            int visited[100100] = {0};
            visited[u] = 1;
            reach = 1;
            while(ttl){
                while(!Q[lev].empty()){
                    k = Q[lev].front();
                    Q[lev].pop();
                    int si = graph[k].size();
                    for(i = 0; i < si; i++){
                        j = graph[k][i];
                        if(visited[j] == 0){
                            reach++;
                            visited[j] = 1;
                            Q[lev+1].push(j);
                        }
                    }
                }
                lev++;
                ttl--;
            }
            printf("Case %lld: %lld nodes not reachable from node %lld with TTL = %lld.\n", kase++, nodes-reach, u, v);
            for(i = 0; i <= lev; i++){
                while(!Q[i].empty())Q[i].pop();
            }
        }
        s.erase(s.begin(), s.end());

        for(i = 0; i <= maxi; i++){
            graph[i].erase(graph[i].begin(), graph[i].end());
        }
    }
    return 0;
}