UVA-10004 BICOLORING

#include<bits/stdc++.h>
using  namespace  std;

#define endl     "\n"
#define ll       long long
#define PI       acos(-1.0)
#define test     cout<<"\n****\n"
#define LCM(a,b) ((a/__gcd(a,b))*b)
#define precise  fixed(cout);cout<<setprecision(20)
#define fast     ios_base :: sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)


vector<int>grap[210];
char color[210];
bool BFS(int node,int root){

    memset(color,'*',sizeof(color));
    color[root] = 'R';

    queue<int> que;
    que.push(root);

    while (!que.empty()){

        int parent = que.front();
        que.pop();
        char childColor;
        if(color[parent]=='R'){
            childColor = 'L';
        } else{
            childColor = 'R';
        }

        for (int i = 0; i < grap[parent].size(); i++) {
            int child = grap[parent][i];
            if(color[child]=='*'){
                color[child] = childColor;
            } else if(color[child]==color[parent]){
                return false;
            }else{
                continue;
            }
            que.push(child);
        }
    }

    return true;
}

int main() {
    fast;
    int node,edge;
    while (cin>>node && node){

        cin>>edge;
        int nod,ed;
        for(int i=0;i<edge;i++){
            cin>>nod>>ed;
            grap[nod].push_back(ed);
            grap[ed].push_back(nod);
        }

        if(BFS(node,nod)){
            cout<<"BICOLORABLE.\n";
        } else{
            cout<<"NOT BICOLORABLE.\n";
        }

        for (auto& v : grap) {
            v.clear();
        }
    }

    return 0;
}