I have a wrong output. MINE is :

P sa 8

P li 7

P he 9

P tu 5

F li 7 tu 5

F li 7 he 9

F tu 5 sa 8

L tu 5

li 7 sa 8

L sa 8

tu 5

U li 7 tu 5

L tu 5

sa 8

Q li 7 he 9

Yes

Q he 9 li 7

Yes

Q he 9 li 23

No

Q he 9 he 9

No

but here is the intended input and output:

INPUT OUTPUt

* p john 8

* p mike 7

* p sara 9

* p jane 5

* f mike 7 jane 5

* f mike 7 sara 9

* f jane 5 john 8

* l jane 5 mike 7 john 8

* l john 8 jane 5

* u mike 7 jane 5

* l jane 5 john 8

* q mike 7 sara 9 yes

* q sara 9 mike 7 yes

* q sara 9 mike 23 no

* q sara 9 sara 9 no

Heres my code:

public class MyFB {

public static boolean DEBUG = true;

public static Person makePerson (In in) {

try {

String name = in.readString ();

int age = in.readInt ();

return makePerson (name, age);

} catch (java.util.InputMismatchException e) {

StdOut.println ("Input format error");

return null;

}

}

Person k;

HashMap> map;

public MyFB() {

map = new HashMap>();

}

public MyFB(HashMap> map) {

this.map = map;

}

public HashMap> getMap() {

return map;

}

public static Person makePerson (String name, int age) {

return new Person (name, age);

}

static class Person {

String name;

int age;

public Person (String name, int age) {

this.name = name;

this.age = age;

}

public String toString () {

return name + " " + age;

}

@Override

public boolean equals (Object obj) {

if(this== obj)

return true;

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

this.getClass()))

return false;

Person t = (Person) obj;

return age == t.age && (name == t.name || (name != null && name.equals(t.name)));

}

@Override

public int hashCode () {

int hash = 31;

hash = 31 * hash + ((Integer) age).hashCode();

hash = 31 * hash + (null == name ? 0 : name.hashCode());

return hash;

}

}

// a person "exists" after they are added using addPerson

// addPerson does nothing if p already exists

public void addPerson (Person p) {

if (DEBUG) {

StdOut.format("P %s ", p);

}

if (map.containsKey(p)) {

return;

}

map.put(p, new HashSet());

}

// addFriendship does nothing if p1 and p2 are already friends or if one does not exist

public void addFriendship (Person p1, Person p2) {

if (DEBUG) {

StdOut.format("F %s %s ", p1, p2);

}

if (p1.equals(p2)) {

return;

}

if (!map.containsKey(p1) || !map.containsKey(p2)) {

return;

}

HashSet s1 = map.get(p1);

HashSet s2 = map.get(p2);

if(!s1.contains(p2))

{

s1.add(p2);

s2.add(p1);

}

}

// removeFriendship does nothing if p1 and p2 are not friends or if one does not exist

public void removeFriendship (Person p1, Person p2) {

if (DEBUG) {

StdOut.format("U %s %s ", p1, p2);

}

if (p1.equals(p2)) {

return;

}

if (!map.containsKey(p1) || !map.containsKey(p2)) {

return;

}

HashSet s1 = map.get(p1);

HashSet s2 = map.get(p2);

if(s1.contains(p2))

{

s1.remove(p2);

s2.remove(p1);

}

}

// queryFriendship returns false if p1 and p2 are not friends or if one does not exist

public boolean queryFriendship (Person p1, Person p2) {

if (DEBUG) {

StdOut.format("Q %s %s ", p1, p2);

}

if (p1 == p2) {

return false;

}

if (!map.containsKey(p1) || !map.containsKey(p2)) {

return false;

} else {

HashSet s1 = map.get(p1);

return s1.contains(p2);

}

}

// lookupFriends returns null or empty iterable if p does not exists

public Iterable lookupFriends (Person p) {

if (DEBUG) {

StdOut.format("L %s ", p);

}

if (!map.containsKey(p))

return null;

else {

return map.get(p);

}

}

public static void hashTest () {

Trace.showBuiltInObjects (true);

//Trace.run ();

Person x = makePerson ("bob", 27);

Person y = makePerson ("bob", 27);

Boolean eq = x.equals(y);

Boolean hash = x.hashCode() == y.hashCode();

StdOut.println(x.toString() + " ("+x.hashCode()+") == " + y.toString() + " ("+y.hashCode()+")");

StdOut.println( " Equal Test: " + (eq ? "equal" : "not equal") );

StdOut.println( " Hash Test: " + (hash ? "equal" : "not equal") );

x = makePerson ("mike", 27);

y = makePerson ("john", 29);

eq = x.equals(y);

hash = x.hashCode() == y.hashCode();

StdOut.println(x.toString() + " ("+x.hashCode()+") == " + y.toString() + " ("+y.hashCode()+")");

StdOut.println( " Equal Test: " + (eq ? "equal" : "not equal") );

StdOut.println( " Hash Test: " + (hash ? "equal" : "not equal") );

}

public static void main (String[] args) {

Trace.showBuiltInObjects (true);

//Trace.run ();

hashTest();

/*

* The first line below causes "in" to read from the console. You can

* change this to read from a file, by using something like the line

* below, where "input.txt" is a file you create in your eclipse

* workspace. The file should be in the same folder that contains "src"

* "bin" and "lib":

*/

//In[] inputFiles = new In[] { new In () }; // from console

In[] inputFiles = new In[] { new In ("input.txt") }; // from file

//In[] inputFiles = new In[] { new In ("input.txt"), new In () }; // from file, then console

MyFB fb = new MyFB ();

StdOut.println (" ");

StdOut.println ("Enter one of the following:");

StdOut.println (" P name age -- add person");

StdOut.println (" F name1 age1 name2 age2 -- add friendship");

StdOut.println (" U name1 age1 name2 age2 -- remove friendship");

StdOut.println (" Q name1 age1 name2 age2 -- query friendship");

StdOut.println (" L name age -- lookup friends");

StdOut.println (" R -- restart");

StdOut.println (" X -- exit ");

for (In in : inputFiles) {

while (in.hasNextLine ()) {

String action;

try {

action = in.readString ();

} catch (NoSuchElementException e) { continue; }

//StdOut.println (action); // while debugging, print debugging info here! You can print maps, sets, lists.

switch (action) {

case "P":

case "p": {

Person p = makePerson (in);

fb.addPerson (p);

break;

}

case "F":

case "f": {

Person p1 = makePerson (in);

Person p2 = makePerson (in);

fb.addFriendship (p1, p2);

break;

}

case "U":

case "u": {

Person p1 = makePerson (in);

Person p2 = makePerson (in);

fb.removeFriendship (p1, p2);

//Trace.draw ();

break;

}

case "Q":

case "q": {

Person p1 = makePerson (in);

Person p2 = makePerson (in);

boolean result = fb.queryFriendship (p1, p2);

StdOut.println (result ? "Yes" : "No");

break;

}

case "L":

case "l": {

Person p = makePerson (in);

Iterable result = fb.lookupFriends (p);

if (result != null) {

for (Person friend : result) {

StdOut.print (friend);

StdOut.print (" ");

}

}

StdOut.println ();

break;

}

case "R":

case "r":

fb = new MyFB ();

break;

case "X":

case "x":

System.exit (0);

}

}

}

}

}