ADAORANG - Ada and Orange Tree

I am solving ADAORANG - Ada and Orange Tree question from spoj in java
every time i submit my solution ,getting TlE after 15 case ,can any one help here how to solve this quetions
or find mistake from code which i am making and explain
Thank you in Advance.
here is my code:
import java.util.;
import java.io.
;
import java.lang.*;

class sparse{
static ArrayList<ArrayList>st;
static ArrayList<ArrayList> part;
static int height[];
static BitSet []bit;
static void dfs(int node ,int source,int h){
height[node]=h;
//part[node][0]=source;
part.get(node).add(0,source);
Iteratorit=st.get(node).iterator();
while(it.hasNext()){
int p=(int)it.next();
if(p!=source){
dfs(p,node,h+1);
bit[node].or(bit[p]);
}
}
}
static void preprocess(int n,int root){
for(int i=0;i<n;i++){
for(int j=0;(1<<j)<n;j++){
part.get(i).add(j,-1);
}
}
dfs(root,-1,0);
for(int j=1;(1<<j)<n;j++){
for(int i=0;i<n;i++){
if(part.get(i).get(j-1)!=-1){
part.get(i).add(j, part.get(part.get(i).get(j-1)).get(j-1));
}
}
}

}

static int lca(int p,int q,int n){

if(height[p]<height[q]){
p=p^q;
q=p^q;
p=p^q;
}
int lg=1;
for(lg=1;(1<<lg)<=height[p];lg++);
lg–;

for(int i=lg;i>=0;i–){
if(height[p]-(1<<i)>=height[q]){
p=part.get(p).get(i);
}
}
if(p==q)
return p;

for(int i=lg;i>=0;i–){
if(part.get(p).get(i)!=-1 && part.get(p).get(i)!=part.get(q).get(i)){
p=part.get(p).get(i);
q=part.get(q).get(i);
}
}
return part.get(p).get(0);
}

public static void main(String[]args) throws java.lang.Exception{
InputReader in = new InputReader(System.in);
OutputWriter out = new OutputWriter(System.out);
int t=in.readInt();
while(t–>0){
int n=in.readInt();
int m=in.readInt();
int root=in.readInt();

       bit=new BitSet[n];
	  
	   for(int i=0;i<n;i++){
		    
         bit[i]=new BitSet(252);
	   }
	   for(int i=0;i<n;i++){
		  
	       int x=in.readInt();
		    bit[i].set(x);
	   }
	   st=new ArrayList<ArrayList<Integer>>();
      for(int i=0;i<n;i++){
      st.add(i,new ArrayList<Integer>());
       }
	   
		  for(int j=0;j<n-1;j++){
			  int x=in.readInt();
		      int y=in.readInt();
		      st.get(x).add(y);
		       st.get(y).add(x);
		  }
		  
		part=new ArrayList<ArrayList<Integer>>();
           for(int i=0;i<n;i++){
           part.add(i,new ArrayList<Integer>());
           }
		height=new int[n]; 
	//	v=new boolean[n];
         preprocess(n,root);
   while(m-->0){
   int u=in.readInt();
   int v=in.readInt();
   int lc=lca(u,v,n);
   System.out.println(bit[lc].cardinality());
   }
	}

}
private static class InputReader
{
private InputStream stream;
private byte[] buf = new byte[1024];
private int curChar;
private int numChars;
private SpaceCharFilter filter;

    public InputReader(InputStream stream)
    {
        this.stream = stream;
    }

    public int read()
    {
        if (numChars == -1)
            throw new InputMismatchException();
        if (curChar >= numChars)
        {
            curChar = 0;
            try
            {
                numChars = stream.read(buf);
            } catch (IOException e)
            {
                throw new InputMismatchException();
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }

    public int readInt()
    {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-')
        {
            sgn = -1;
            c = read();
        }
        int res = 0;
        do
        {
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }

    public String readString()
    {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        StringBuilder res = new StringBuilder();
        do
        {
            res.appendCodePoint(c);
            c = read();
        } while (!isSpaceChar(c));
        return res.toString();
    }

    public double readDouble()
    {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-')
        {
            sgn = -1;
            c = read();
        }
        double res = 0;
        while (!isSpaceChar(c) && c != '.')
        {
            if (c == 'e' || c == 'E')
                return res * Math.pow(10, readInt());
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        }
        if (c == '.')
        {
            c = read();
            double m = 1;
            while (!isSpaceChar(c))
            {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, readInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                m /= 10;
                res += (c - '0') * m;
                c = read();
            }
        }
        return res * sgn;
    }

    public long readLong()
    {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-')
        {
            sgn = -1;
            c = read();
        }
        long res = 0;
        do
        {
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }

    public boolean isSpaceChar(int c)
    {
        if (filter != null)
            return filter.isSpaceChar(c);
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }

    public String next()
    {
        return readString();
    }

    public interface SpaceCharFilter
    {
        public boolean isSpaceChar(int ch);
    }
}

private static class OutputWriter
{
    private final PrintWriter writer;

    public OutputWriter(OutputStream outputStream)
    {
        writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
    }

    public OutputWriter(Writer writer)
    {
        this.writer = new PrintWriter(writer);
    }

    public void print(Object... objects)
    {
        for (int i = 0; i < objects.length; i++)
        {
            if (i != 0)
                writer.print(' ');
            writer.print(objects[i]);
        }
    }

    public void printLine(Object... objects)
    {
        print(objects);
        writer.println();
    }

    public void close()
    {
        writer.close();
    }

    public void flush()
    {
        writer.flush();
    }
}

}