Dutch national flag problem in Javascript

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Dutch national flag problem and solution in Javascript Problem statement:   The Dutch national flag (DNF) problem is one of the most popular programming problems proposed by Edsger Dijkstra. The flag of the Netherlands consists of three colors: white, red, and blue. The task is to randomly arrange balls of white, red, and blue such that balls of the same color are placed together. Now, let's consider an array with 3 distinct values say 0, 1 and 2. We won't be using any sort method and we need to sort this array in 0(n). Input Array :  let   arr  = [ 0 ,  2 ,  1 ,  0 ,  1 ,  2 ,  0 ,  2 ]; Expected Output: [ 0, 0, 0, 1, 1, 2, 2, 2 ] Solution Approach : When we see expected output, we can clearly see that sorted array is divided into 3 sections having values 0 , 1 and 2. So, let's divide the array in 3 sections: a) from 0th index to left boundary b) from left boundary to right boundary c) from right boundary to last index. Now we will create 2 pointers : left (starting from 0
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Day 4: Count Objects (Hackerrank 10 days of Javascript) Problem and solution

 

Objective::

In this challenge, we learn about iterating over objects.

Task::

Complete the function in the editor. It has one parameter: an array, a , of objects. Each object in the array has two integer properties denoted by x and  y. The function must return a count of all such objects o in array a  that satisfy o.x==o.y.

Input Format::

The first line contains an integer denoting n.
Each of the n subsequent lines contains two space-separated integers describing the values of x and y.

Constraints::

·       5 <= n <= 10

·       1 <=x, y<=100

Output Format

Return a count of the total number of objects o such that o.x==o.y. Locked stub code in the editor prints the returned value to STDOUT.

Sample Input 0

5

1 1

2 3

3 3

3 4

4 5

Sample Output 0

2

Explanation 0

There are “n=5” objects in the “object” array:

Because we have two objects o  that satisfy o.x==o.y (i.e., 1 1 and 3 3), we return  as our answer.

 

 

Solution 1 :

/*

 * Return a count of the total number of objects 'o' satisfying o.x == o.y.

 * 

 * Parameter(s):

 * objects: an array of objects with integer properties 'x' and 'y'

 */

 

function getCount(objects) {

var count = 0;

 

Object.keys(objects).forEach((key,index)=>{

    if(objects[key].x === objects[key].y){

    count++;}

})

    return count;

    

}

 

Solution 2:

/*

 * Return a count of the total number of objects 'o' satisfying o.x == o.y.

 * 

 * Parameter(s):

 * objects: an array of objects with integer properties 'x' and 'y'

 */

 

function getCount(objects) {

var count = 0;

 

objects.forEach(function (o){

    if (o.x===o.y){

        count++;

    }

})

    return count;

    

}

Hackerrank Problem link: https://www.hackerrank.com/challenges/js10-count-objects/problem

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