Hacker Rank Frequency Queries [closed]

I am doing the Hacker Rank Frequency Queries question and all my test cases pass but one for Time limit exceeded. What can I do to make my program more efficient. static List freqQuery(…

Connect two HashMap Values

I’ve got this JSON string: String json = “{“countries”:{“2″:”China”,”3″:”Russia “,”4″:”USA”},”capitals&…

How to properly add a value change listener to Map.Entry?

A project im working on currently requires me to ensure that while looping through a map’s entries, if Entry.setValue is called, it would trigger a value change event. I see I can try something like …

Hashcode value for Map Entry

As per javadocs hashcode for a map.entry is defined as : int hashCode() Returns the hash code value for this map entry. The hash code of a map entry e is defined to be: (e.getKey()==null ? 0 : …

Why any initialization or even print inside the constructor with @Tolerate lombok cannot be reached?

what is the problem with the constructor with @Tolerate of lombok, and why it cannot be reached? and how can I fix it? I wanna initialize a map by setting some default keys and values inside the …

How does get method works in hashmap if hashcode returns a contant value and equals return false?

I have Dept class as follows, i have overridden hashcode and equals method. Hashcode returns a constant value and equals return false always. public class Dept { private int depid; …

Converting String number words to just String number:Java

I’m a beginner coder trying to work on converter for words which should work that way:Input= “zero;six;eight;two” Output = “0682”. But in my case the output I get is “0282&…

Create arraylist from list of maps for certain key value with java 8

I have an object with a list of maps. Each map looks like this: { id: “something”, link: “someLink” } I am trying to create an array list of all the id’s in the maps. I can do …

Static method to count occurrences of a letter in a lower case word using maps

I have to create a class called MakeMap with a single static method called countLetters(). The method should take as a parameter a word formed of lowercase letters and return a map of the counts of …

Why does clear hashmap method clears added map in array list

I’m trying to reuse same HashMap like in example bellow to populate list. First I put some values in the map, add map to the list and then clear map in order to put again new values and add second set …