Untitled

 
import java.util.Map;
import java.util.TreeMap;
 
class UserSolution
{
    TreeMap<Integer, Integer> map[];
     
    public void init()
    {
        map = new TreeMap[102];
         
        for(int i=0;i<102;i++) {
            map[i] = new TreeMap<Integer, Integer>();
        }
    }
 
    public void add(int mX, int mY)
    {
        map[mX].put(mY, mX+1);
        map[mX+1].put(mY, mX);
    }
 
    public void remove(int mX, int mY)
    {
        map[mX].remove(mY);
        map[mX+1].remove(mY);
    }
 
    public int numberOfCross(int mID)
    {
        int cnt =0;
         
        int mX = mID;
        int mY = 0;
         
        while (true) {
            Map.Entry<Integer, Integer> mpEntry = map[mX].higherEntry(mY);
             
            if(mpEntry==null) break;
             
            mX = mpEntry.getValue();
            mY = mpEntry.getKey();
            cnt++;
        }
         
        return cnt;
    }
 
    public int participant(int mX, int mY)
    {
        while (true) {
            Map.Entry<Integer, Integer> mpEntry = map[mX].lowerEntry(mY);
             
            if(mpEntry==null) break;
             
            mX = mpEntry.getValue();
            mY = mpEntry.getKey();
        }
         
        return mX;
    }
 
}