Abhishek-Chaudhary-InfoCepts

/**
 * Definition for an interval. public class Interval { int start; int end;
 * Interval() { start = 0; end = 0; } Interval(int s, int e) { start = s; end =
 * e; } }
 */
class MergeIntervals {
	public List<Interval> merge(List<Interval> intervals) {
		
        if (intervals.size() < 0) {
			return null;

Abhishek-Chaudhary-InfoCepts

class GroupAnagrams {
    public List<List<String>> groupAnagrams(String[] strs) {
        HashMap<String, List> map = new HashMap<String, List>();
        for (String word: strs){
            char[] chars = word.toCharArray();
            // sorting changes original data structure
            Arrays.sort(chars);
            // short for converting character array to string
            String key = String.valueOf(chars);
            if (!map.containsKey(key)){

Abhishek-Chaudhary-InfoCepts

import java.util.ArrayDeque;
import java.util.Deque;

public class MaxStack {
    private Deque<Integer> stack = new ArrayDeque<>();
    private Deque<Integer> maxesStack = new ArrayDeque<>();
    // Add a new item to the top of our stack. If the item is greater
    // than or equal to the last item in maxesStack, it's
    // the new max! So we'll add it to maxesStack.
    public void push(int item) {

Abhishek-Chaudhary-InfoCepts

package com.abhishek.dojo.lru;

import java.util.Iterator;
import java.util.LinkedHashMap;


public class LRUCache {

	private int capacity;
	// use linkedhashmap to maintain the sequence

Abhishek-Chaudhary-InfoCepts

package com.abhishek.dojo;

import java.util.HashMap;
import java.util.Map;

public class WordCloud {
	private Map<String, Integer> wordsToCounts = new HashMap<String, Integer>();

	public WordCloudData(String inputString) {
		populateWordsToCounts(inputString);

Abhishek-Chaudhary-InfoCepts

package com.abhishek.dojo.arrays;

//reference- https://www.youtube.com/watch?v=CGMNePwovA0

public class NumberofIslandsChar {

	public static void main(String[] args) {
		NumberofIslandsChar n = new NumberofIslandsChar();
		// expected = 3
		char[][] grid = { { '1', '1', '0', '0', '0' }, 

Abhishek-Chaudhary-InfoCepts

package com.abhishek.dojo.arrays;

import java.util.ArrayList;
import java.util.Arrays;

public class MergeSortedArrays {

	public static int[] mergeArrays(int[] firstArr, int[] secondArr) {
		ArrayList test = new ArrayList(Arrays.asList("a", "b", "c"));
		// combine the sorted arrays into one large sorted array

Abhishek-Chaudhary-InfoCepts

package com.abhishek.dojo;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map.Entry;
import java.util.PriorityQueue;

public class TopKRepeatingElements {
	class Pair {
		int num;

Abhishek-Chaudhary-InfoCepts

package com.abhishek.dojo;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Optional;

public class LongestIncreasingSubsequence {

	public static void main(String[] args) {

Abhishek-Chaudhary-InfoCepts

package com.abhishek.dojo;

import java.util.HashSet;

/*Write an algorithm to determine if a number 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