ozkansari’s gists

ozkansari / CountingConsecutiveElements.java

Last active April 13, 2020 06:30

Given an integer array arr, count element x such that x + 1 is also in arr. If there're duplicates in arr, count them seperately. https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/528/week-1/3289/

	import java.util.*;
	import java.util.stream.*;

	class CountingConsecutiveElements {

	public int countElements(int[] arr) {

	Map<Integer, Integer> numberCounts = new HashMap<>();
	for(int num : arr) {
	Integer wrappedNum = Integer.valueOf(num);

ozkansari / GroupAnagrams2.java

Created April 12, 2020 20:34

Given an array of strings, group anagrams together. https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/528/week-1/3288/

	import java.util.*;
	import java.util.stream.*;
	import static java.util.stream.Collectors.*;

	class GroupAnagrams2 {

	public List<List<String>> groupAnagrams(String[] wordsArray) {
	Map<String,List<String>> anagramWords = new HashMap<>();
	for(String word : wordsArray) {
	String key = calculateKey(word);

ozkansari / GroupAnagrams.java

Last active April 12, 2020 20:34

Given an array of strings, group anagrams together. https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/528/week-1/3288/

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.stream.Collectors;

	public class GroupAnagrams {
	public static void main(String[] args) {
	GroupAnagrams problem = new GroupAnagrams();
	List<List<String>> result1 = problem.groupAnagrams(new String[] { "eat", "tea", "tan", "ate", "nat", "bat" });

ozkansari / MoveZeroesOptimal.java

Created April 12, 2020 18:34

Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements. https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/528/week-1/3286/

	import java.util.Arrays;
	import java.util.stream.Collectors;

	public class MoveZeroesOptimal {

	public static void main(String[] args) {
	MoveZeroesOptimal problem = new MoveZeroesOptimal();
	int[] result1 = problem.calculate(new int[] { 0, 1, 0, 3, 12 });
	System.out.println(
	"Expected: [1,3,12,0,0], " + "Result: " + Arrays.stream(result1).boxed().collect(Collectors.toList()));

ozkansari / MoveZeroes.java

Created April 12, 2020 18:22

Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements. https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/528/week-1/3286/

	import java.util.Arrays;
	import java.util.stream.Collectors;

	public class MoveZeroes {

	public static void main(String[] args) {
	MoveZeroes problem = new MoveZeroes();
	int[] result1 = problem.calculate(new int[] { 0, 1, 0, 3, 12 });
	System.out.println(
	"Expected: [1,3,12,0,0], " + "Result: " + Arrays.stream(result1).boxed().collect(Collectors.toList()));

ozkansari / MaxSubArray.java

Created April 12, 2020 17:21

Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum. https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/528/week-1/3285/

	public class MaxSubArray {

	public static void main(String[] args) {
	MaxSubArray problem = new MaxSubArray();

	int result1 = problem.calculate(new int[] { -2,1,-3,4,-1,2,1,-5,4 });
	System.out.println("Expected: 6, Result: " + result1);
	}

	public int calculate(int[] nums) {

ozkansari / HappyNumber.java

Created April 12, 2020 16:34

Write an algorithm to determine if a number n is "happy". A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Th…

	import java.util.ArrayList;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Set;

	public class HappyNumber {

	public static void main(String[] args) {
	HappyNumber problem = new HappyNumber();
	boolean result1 = problem.isHappy(19);

ozkansari / LinkedListMiddleNodeFastPointer.java

Created April 12, 2020 16:03

Middle of the Linked List : Given a non-empty, singly linked list with head node head, return a middle node of linked list. If there are two middle nodes, return the second middle node. https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/529/week-2/3290/

	/**
	* Definition for singly-linked list.
	* public class ListNode {
	* int val;
	* ListNode next;
	* ListNode(int x) { val = x; }
	* }
	*/
	class LinkedListMiddleNodeFastPointer {
	public ListNode middleNode(ListNode head) {

ozkansari / LinkedListMiddleNode.java

Created April 12, 2020 14:46

Middle of the Linked List : Given a non-empty, singly linked list with head node head, return a middle node of linked list. If there are two middle nodes, return the second middle node. https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/529/week-2/3290/

	/**
	* Definition for singly-linked list.
	* public class ListNode {
	* int val;
	* ListNode next;
	* ListNode(int x) { val = x; }
	* }
	*/
	class LinkedListMiddleNode {

ozkansari / BinaryTreeDiameterCalculatorWithRecursion.java

Created April 12, 2020 13:59

Given a binary tree, you need to compute the length of the diameter of the tree. The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root. https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/529/week-2/3293/

	/**
	* Definition for a binary tree node.
	* public class TreeNode {
	* int val;
	* TreeNode left;
	* TreeNode right;
	* TreeNode(int x) { val = x; }
	* }
	*/

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