Problems:

Reverse a singly linked list

Remove duplicated in a sorted linked list

Submission First, look at the following checklist:

$$ Have you tested every method?

$$ Is the indentation easily readable? You can have Eclipse correct indentation by highlighting all

code and select "Source $>$ Correct Indentation".

$$ Are comments well organized and concise?

Grading Criteria

$$ Sort an array $(20$p$)$

$$ Find the kth largest element in an array, not sorted $(15$p$)$

$$ Reverse a singly linked list $(20$p$)$

$$ Remove duplicated in a sorted linked list $(20$p$)$

$$ Complete the $4$ unimplemented test cases $(3$ in ArrayProblemsTest.java and $1$ in LinkedListProb$-$

lemsTest.java$)(20$p$)$

$$ Source code is appropriately commented $(5$p$)$

public class LinkedListProblems $\{$

$/*$

Given a sorted linked list, delete all duplicates such that each element appear only once.

Example $1$:

Input: $1->1->2$

Output: $1->2$

Example $2$:

Input: $1->1->2->3->3$

Output: $1->2->3$

$*/$

public static ListNode deleteDuplicates$($ListNode head$)\{$

$//$TODO: finish this method.

$//$TODO: Modify this line to return correct data.

return null;

$\}$

$/*$

$*$ Reverse a singly linked list.

Example:

Input: $1->2->3->4->5->$NULL

Output: $5->4->3->2->1->$NULL

$*/$

public static ListNode reverseList$($ListNode head$)\{$

$//$TODO:finish this method.

$//$TODO: Modify this line to return correct data.

return null;

$\}$

$\}$

import static org.junit.Assert.assertEquals;

import static org.junit.Assert.fail;

import org.junit.Before;

import org.junit.Test;

public class LinkedListProblemsTest $\{$

ListNode T;

$/*$ The common test data to be used is the list T: $1->1->2->3->3$

$*/$

@Before

public void setUp$()$ throws Exception $\{$

int$[]$ testdata$=\{1,1,2,3,3\}$;

ListNode T $=$ new ListNode$($testdata$[1])$;

for $($int i$=1$; i$1->2->3->3->$null

Output: $1->2->3->$null

$*/$

@Test

public void testDeleteDuplicates$()\{$

int$[]$ expected $=\{1,2,3\}$;

ListNode newT$=$LinkedListProblems.deleteDuplicates$($T$)$;

ListNode p$=$newT;

int i $=0$;

while $($p$!=$null$)\{$

assertEquals$($expected$[$i$],$ p$.$val$)$;

i $=$ i$+1$;

$\}$

$\}$

$/*$

$*$ Reverse a singly linked list.

Example:

Input: $1->1->2->3->3->$NULL

Output: $3->3->1->1->1->$NULL

$*/$

@Test

public void testReverseList$()\{$

fail$("$Not yet implemented"$)$; $//$ TODO

$\}$

$\}$

public class ListNode $\{$

int val;

ListNode next;

ListNode$($int x$)\{$ val $=$ x; $\}$

$\}$

Please Complete them