Can someone help me fix this code

mport java.io.BufferedReader;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.IOException;

import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Hashtable;

import java.util.List;

import java.util.Map;

import java.util.Scanner;

import java.util.Stack;

public class Driver {

static ArrayList users = new ArrayList();

static Scanner input = new Scanner(System.in);

public static void main(String[] args) {

String filename;

String line;

int userID, followID, depth;

TwitterUser userObj, followObj, cloneTestObj;

/*

* Reading file and pulling in data

*/

/**/

System.out.print("nEnter the filename holding the user data:");

// filename = input.nextLine();//*/

filename = "social_network.edgelist";

//filename = "finalTestList.edgelist";

long startTime = System.currentTimeMillis();

long endTime;

System.out.println("nTesting the file input: ");

try {

BufferedReader file = new BufferedReader(newFileReader(filename));

System.out.println("tReading data from the file...");

Stack followers = new Stack();

HashSet hashSet = new HashSet(1000000);

while ((line = file.readLine()) != null &&!line.isEmpty()) {

String[] ids = line.split(" ");

userID = Integer.parseInt(ids[0]);

followID = Integer.parseInt(ids[1]);

hashSet.add(new TwitterUser(userID));

hashSet.add(new TwitterUser(followID));

// Followers begin

followers.push(new Integer[] { userID, followID });

// Followers end

}

endTime = System.currentTimeMillis();

System.out.println("tFinished adding " + hashSet.size()

+ " users in " + (int) ((endTime - startTime) / 1000)

+ " seconds.");

file.close();

// Map all TwitterUsers to their ID in HashMap

HashMap hashMap = new HashMap();

for (TwitterUser t : hashSet) {

hashMap.put(t.getID(), t);

}

file = new BufferedReader(new FileReader(filename));

startTime = System.currentTimeMillis();

int counter = 0;

System.out.println("ntFriending...");

while ((line = file.readLine()) != null &&!line.isEmpty()) {

String[] ids = line.split(" ");

userID = Integer.parseInt(ids[0]);

followID = Integer.parseInt(ids[1]);

userObj = hashMap.get(userID);

followObj = hashMap.get(followID);

userObj.followUser(followObj);

counter++;file.close();

endTime = System.currentTimeMillis();

System.out.println("tFinished all " + counter

+ " friending operations in "

+ (int) ((endTime - startTime) / 1000) + " seconds.");

// Transfer HashMap values to ArrayList of TwitterUsers

for (TwitterUser t : hashMap.values()) {

users.add(t);

}

// Followers begin

mapFollowers(followers);

// Followers end

} catch (FileNotFoundException e) {

System.out.println("ntThe filename "" + filename

+ "" was not found. Exiting program.");

System.exit(1);

} catch (IOException i) {

System.out.println("tIOException: ");

i.printStackTrace();

}

/**

* System.out.println("ntUsers:"); for (TwitterUser t: users){

* System.out.println("tUser " + t); }/

**/

/*

* Unit test of the getNeighborhood function

*/

System.out

.print("nTest for the getNeighborhood(user, depth)function:"

+ "ntEnter the user you would like to test: ");

userID = input.nextInt();

userObj = getUser(userID);

System.out

.print("tEnter the depth you would like to go to in yourneighborhood: ");

depth = input.nextInt();

while (depth < 0 || (depth >userObj.getFollowing().size())) {

System.out

.print("tPlease enter a positive number less than or equal to"

+ userObj.getFollowing().size() + ": ");

depth = input.nextInt();

}

userObj.getNeighborhood(userObj, depth);

/** Clone method test

*/

final int TEST_USER = 0;

System.out.println("nTesting the clone() function for deepcopy:");

userObj = getUser(TEST_USER);

System.out.println("tCloning User " + userObj + ".");

cloneTestObj = (TwitterUser) userObj.clone();

System.out.println("tUser " + userObj + " successfullycloned.");

System.out.println("tUser 0's following list: "

+ userObj.getFollowing() + "ntClone's following list: "

+ cloneTestObj.getFollowing());

System.out.print("tClearing the clone's following list.");

cloneTestObj.clearFollowing();

System.out.println("ntUser 0's following list: "

+ userObj.getFollowing() + "ntClone's following list: "

+ cloneTestObj.getFollowing());

// Followers test begin

System.out.print("nTest for the followers function:"

+ "ntEnter the user you would like see list of followers:");

userID = input.nextInt();

test_getFollowing(getUser(userID));

// Followers test end

// Popularity test begin

System.out

.print("nTest for the followers getByPopularity function:"

+ "ntEnter the user index for which you would like to seepopularity: ");

int idx = input.nextInt();

TwitterUser u = getByPopularity(idx);

System.out.print("nThe " + idx + "th popular user is :" +u.getID()

+ " number of followers " + u.getFollowers().size());

// Popularity test end

System.out.println("nnExiting.");

}

public static TwitterUser getUser(int userID) {

TwitterUser temp;

temp = new TwitterUser(userID);

while (!users.contains(temp)) {

System.out.print("tInvalid user ID. Enter a valid user id:");

userID = input.nextInt();

temp.setUserID(userID);

}

return users.get(users.indexOf(temp));

}

// Followers && Popularity begin

/**

* Walk through the list of users and find match

*

* @param followers

*

*/

private static void mapFollowers(Stack followers) {

while (!followers.isEmpty()) {

Integer[] anEntry = followers.pop();

Integer aUserId = anEntry[1];

List f = findFollowersForUser(

(Stack) followers.clone(), aUserId);

System.err.println("User " + aUserId + " has " + f.size()

+ " followers.");

TwitterUser aUser = getUser(aUserId);

aUser.setFollowers(f);

}

}

/**

* given a userID id find all followers in stack

*

* @param sList

* @param id

* @return a list of followers

*/

private static List findFollowersForUser(Stack sList,

Integer id) {

List f = new ArrayList();

while (!sList.isEmpty()) {

Integer[] ids = sList.pop();

if (id - ids[1] == 0) {

f.add(ids[0]);

// System.err.println(ids[0] +" : "+ ids[1]);

}

}

return f;

}

public static void test_getFollowing(TwitterUser user) {

Collection followerUsers = user.getFollowing(user);

List followers = new ArrayList();

for (TwitterUser aUser : followerUsers) {

followers.add(aUser.getID());

}

System.out.println("User " + user.getID() + " has " +followers

+ " followers. ");

}

private static TwitterUser getByPopularity(int idx) {

Collections.sort(users, new UserComparator());

return users.get(idx);

}

// Followers && Popularity end

}

import java.util.ArrayList;

import java.util.Collection;

import java.util.List;

public class TwitterUser implements Comparable, Cloneable {

private int id;

private ArrayList following = new ArrayList();

public TwitterUser() {

}

public TwitterUser(int userID) {

id = userID;

}

public void getNeighborhood(TwitterUser user, int depth) {

System.out.println("tUser " + user + ", Friends: "

+ user.getFollowing());

if (depth <= 0) {

// do nothing

} else {

for (int i = 0; i < depth; i++) {

TwitterUser temp = following.get(i);

getNeighborhood(temp, 0);

}

}

} public void followUser(TwitterUser user) {

if (!following.contains(user)) {

following.add(user);

}

}

public void clearFollowing() {

following.clear();

}

public ArrayList getFollowing() {

ArrayList copy = new ArrayList();

for (TwitterUser t : following) {

copy.add(t);

}

return copy;

}

public int getID() {

return id;

}

public void setUserID(int newId) {

id = newId;

}

@Override

public int compareTo(TwitterUser t) {

if (id > t.getID()) {

return 1;

} else if (id < t.getID()) {

return -1;

} else {

return 0;

}

}

@Override

public int hashCode() {

final int prime = 31;

int result = 1;

result = prime * result + id;

return result;

}

@Override

public boolean equals(Object obj) {

if (this == obj)

return true;

if (obj == null)

return false;

if (getClass() != obj.getClass())

return false;

TwitterUser other = (TwitterUser) obj;

if (id != other.id)

return false;

return true;

}

public Object clone() {

try {

TwitterUser clonedUser = (TwitterUser) super.clone();

clonedUser.following = (ArrayList) following.clone();

return clonedUser;

} catch (CloneNotSupportedException e) {

return null;

}

}

public String toString() {

return Integer.toString(id);

}

// Followers begin

/*

*

* return a collection of the people who are following theuser

*/

public Collection getFollowing(TwitterUser user) {

Collection tUser = new ArrayList();

if (user.getID() == 415) {

System.out.print("nuser id: " + user.getID());

for (Integer t : user.getFollowers()) {

tUser.add(new TwitterUser(t));

}

return tUser;

}

private List followers = new ArrayList<>();

public void setFollowers(List f) {

for (Integer i : f) {

if (!followers.contains(i))

followers.add(i);

}

}

public List getFollowers() {

return followers;

}

// Followers end

}

import java.util.Comparator;

public class UserComparator implements Comparator {

@Override

public int compare(TwitterUser o1, TwitterUser o2) {

int res = 0;

// 3. If two users have the same number of followers and arefollowing

// the same number of people, sort by user id (smallest tolargest)

if ((o1.getFollowers().size() == o2.getFollowers().size())

&& (o1.getFollowing().size() ==o2.getFollowing().size()))

res = (o1.getID() < o2.getID() ? 1 : 0);

// 2. If two users have the same number of followers, sort bythe number

// of people that user is following (largest to smallest)

if (o1.getFollowers().size() == o2.getFollowers().size())

res = o1.getFollowing().size() > o2.getFollowing().size() ? 1: 0;

// 1. Number of followers (largest to smallest)

if (o1.getFollowers().size() > o2.getFollowers().size())

res = 1;

return res;

}

}