ali-alaei

class Solution {
    Map<String, List<String>> adjList = new HashMap<String, List<String>>();
    List<String> currPath = new ArrayList<String>();
    List<List<String>> shortestPaths = new ArrayList<List<String>>();

    public List<List<String>> findLadders(String beginWord, String endWord, List<String> wordList) {
        // copying the words into the set for efficient deletion in BFS
        Set<String> copiedWordList = new HashSet<>(wordList);
        // build the graph using BFS
        bfs(beginWord, endWord, copiedWordList);

ali-alaei

class Solution {
  public String alienOrder(String[] words) {
       //For catching Errors
       if(words.length==0) return "";
       //The dependencyMap and countMap data structures 
       Map<Character, Set<Character>> dependencyMap = new HashMap<>();
       Map<Character, Integer> countMap = new HashMap<>();
       //a boolean that determines whether we can build a graph or not
       boolean success = buildGraph(words, dependencyMap, countMap);
       if(!success) return "";

ali-alaei

import java.util.*;

class TrieNode {
 //Hash map of character to trie node
 HashMap<Character, TrieNode> children = new HashMap<Character, TrieNode>();
 //A string to store the possible found words for each node
 String word = null;
 public TrieNode() {}
}
class Solution {

ali-alaei

import javafx.util.Pair;

import java.util.HashSet;
import java.util.Set;

interface Robot {
   boolean move();

   void turnLeft();

ali-alaei

import java.util.Arrays;
import java.util.Comparator;


public class Solution {

    //A method to return the number of used rooms
    public int minMeetingRooms(int[][] intervals) {

        //If input == null, does not process it

ali-alaei

import java.util.*;

public class Solution {

    //Takes a 2D array as the input
    public int numIslands(char[][] grid) {

        //If empty, returns 0
        if(grid == null || grid.length == 0)
        {

ali-alaei

import java.util.*;

class Solution {

    public int[] findOrder(int numCourses, int[][] prerequisites) {

        //A map to model the graph
        Map<Integer, List<Integer>> adjList = new HashMap<Integer, 
                                                  List<Integer>>();
        //To save the indegree of each node in the graph

ali-alaei

import java.util.*;

public class LRUCache {

    //double linked list class
    class DLinkedNode {
        int key;
        int value;
        DLinkedNode prev;
        DLinkedNode next;

ali-alaei

public class Main
{
     private String findLongestPalindromicSubstring(String input)
    {
        //If empty, does not analyze the string
        if(input.isEmpty())
        {
            return "";
        } 

ali-alaei

class Solution
{
    //The function checks if a substring with given start and end points
    //is a palindrome or not.
    public boolean isPalindrome(String s, int start, int end)
    {
        while (start < end)
        {
            if (s.charAt(start) != s.charAt(end))
                return false;