HackerRank Contest - Project Euler - Largest product in a series

2019-01-07

Solution

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int T = scan.nextInt();
        
        for(int j=0;j<T;j++){
            int N = scan.nextInt();
            int K = scan.nextInt();
            scan.nextLine();
        
            char[] data = scan.nextLine().toCharArray();
        
            int max = 0;
        
            for(int i=0;i<N-K;i++){
                int prod = getProduct(data,i,K);
            
                if(prod>max){
                    max = prod;
                }
            }
        
            System.out.println(max);
        }
        
    }
    
    static int getProduct(char[] data, int start, int length){
        int product = 1;
        
        for(int i=start;i<start+length;i++){
            product = product * Character.getNumericValue(data[i]);
        }
        
        return product;
    }
}

HackerRank Contest - Project Euler - Multiples of 3 and 5

2019-01-07

#HackerRank #Solution #Java

Solution

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        
        Scanner scan  = new Scanner(System.in);
        int numCases = scan.nextInt();
        
        for(int index=0;index<numCases;index++){
            long num = scan.nextInt()-1;
            
            System.out.println(sumOfMultiples(num/3,3)+sumOfMultiples(num/5,5)-sumOfMultiples(num/15,15));
        }
    }
    
    public static long sumOfMultiples(long num, long multiple){
        return (multiple*num*(num+1))/2;
    }
}

Model Relations in Mongoose

2018-12-24

#Topic #Mongoose #Model #Relations

Model Relations

Relations are logical links which define how models are connected with each other. A document of a model can be connected to one or more documents of the same or another model.

Implement a Javascript Client for Crypto Compare API

2018-12-16

#Tutorial #Cligen #NPM #API #Client #JavaScript #Browser

Crypto Compare

Crypto Compare is a website and API provider which brings you all the latest streaming pricing data in the world of cryptocurrencies. Their API documentation is available here.

NPM Module - Complex JSON to Query String

2018-10-17

#Project #NPM #NodeJS

@abskmj/query

It is an NPM module that converts complex JSON with arrays and nested objects into URL parameters or query string. It can also parse such query string back to JSON.

HackerRank - Divisible Sum Pairs

2018-09-10

#HackerRank #Solution #Java

Solution

/* Solution to HackerRank: Divisible Sum Pairs
 * URL: https://www.hackerrank.com/challenges/divisible-sum-pairs
 */
import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

public class Solution {

    // Complete the divisibleSumPairs function below.
    static int divisibleSumPairs(int n, int k, int[] ar) {
        int count = 0;
        
        for(int i=0; i < n; i++){
            for(int j=i+1; j < n; j++){
                if((ar[i]+ar[j])%k == 0){
                    count++;
                }
            }
        }

        return count;
    }

    private static final Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) throws IOException {
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        String[] nk = scanner.nextLine().split(" ");

        int n = Integer.parseInt(nk[0]);

        int k = Integer.parseInt(nk[1]);

        int[] ar = new int[n];

        String[] arItems = scanner.nextLine().split(" ");
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        for (int i = 0; i < n; i++) {
            int arItem = Integer.parseInt(arItems[i]);
            ar[i] = arItem;
        }

        int result = divisibleSumPairs(n, k, ar);

        bufferedWriter.write(String.valueOf(result));
        bufferedWriter.newLine();

        bufferedWriter.close();

        scanner.close();
    }
}

HackerRank - The Time in Words

2018-09-10

#HackerRank #Solution #Java

Solution

/* Solution to HackerRank: The Time in Words
 * URL: https://www.hackerrank.com/challenges/the-time-in-words
 */
import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

public class Solution {

    // Complete the timeInWords function below.
    static String timeInWords(int h, int m) {
        String[] words = {"zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen", "twenty"};
        
        if (m == 0){
            return words[h] + " o' clock";
        } else if (m == 15){
            return "quarter past " + words[h];
        } else if (m == 30){
            return "half past " + words[h];
        } else if (m == 45){
            return "quarter to " + words[h+1];
        } else if (m == 1){
            return "one minute past " + words[h];
        } else if (m == 59){
            return "one minute to " + words[h+1];
        } else if (m < 21){
            return words[m] + " minutes past " + words[h];
        } else if (m > 39){
            return words[60-m] + " minutes to " + words[h+1];
        } else if (m > 30){
            return "twenty " + words[(60-m)%20] + " minutes to " + words[h+1];
        }
        else{            
            return "twenty " + words[m%20] + " minutes past " + words[h];
        }

    }

    private static final Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) throws IOException {
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        int h = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        int m = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        String result = timeInWords(h, m);

        bufferedWriter.write(result);
        bufferedWriter.newLine();

        bufferedWriter.close();

        scanner.close();
    }
}

Developing an Angular project on Cloud9 IDE

2018-07-10

#Angular #NodeJS #NPM #Tutorial #Cloud9 IDE

Update NodeJS version

All of the blank VMs on cloud9 have nvm pre installed.
List all the available versions from the official site.

nvm ls-remote

Choose to install the latest version

nvm install v10.6.0

Choose to use the latest version

nvm use v10.6.0

Check the version in use

node --version

Angular

Install latest Angular CLI package

npm install -g @angular/cli

Create a new project named my-project (you can use any name you need)

ng new my-project
cd my-project

Change start script in package.json

{
  ...
  
  "scripts": {
    ...
    
    "start": "ng serve --host $IP  --port $PORT --public-host $C9_HOSTNAME",
    
    ...
  }
  
  ...
}

On IDE menu, click on Preview > Preview Running Application to get the preview URL.

Downside

Everything works perfectly expect that the live reload, sometimes, is slower than usual.

Using a remote repository with Glitch.com

2018-06-18

#Tutorial #Glitch.com #Git

Glitch is a online workspace that support javascript for development with live previews.

Fix TWRP E3004 Error on OnePlus2

2018-05-18

#Note #Android #CustomROM #LineageOS #TWRP

I have recently installed LineageOS custom ROM on my OnePlus2 device to keep on trying new android versions as they come. While installing/updating the OS, I was getting below error on TWRP recovery screen.