Day 0: Weighted Mean HackerRank Solution

Day 0: Weighted Mean HackerRank Solution
Source : https://www.hackerrank.com/challenges/s10-weighted-mean

Objective
In the previous challenge, we calculated a mean. In this challenge, we practice calculating a weighted mean. Check out the Tutorial tab for learning materials and an instructional video!

Task
Given an array, , of integers and an array, , representing the respective weights of 's elements, calculate and print the weighted mean of 's elements. Your answer should be rounded to a scale of decimal place (i.e., format).

Input Format

The first line contains an integer, , denoting the number of elements in arrays and .
The second line contains space-separated integers describing the respective elements of array .
The third line contains space-separated integers describing the respective elements of array .

Constraints

• , where is the element of array .
• , where is the element of array .

Output Format

Print the weighted mean on a new line. Your answer should be rounded to a scale of decimal place (i.e., format).

Sample Input

510 40 30 50 201 2 3 4 5

Sample Output

32.0

Explanation

We use the following formula to calculate the weighted mean:

And then print our result to a scale of decimal place () on a new line.

Source : https://www.hackerrank.com/challenges/s10-weighted-mean

Solution

	// github.com/RodneyShag
	import java.util.Scanner;
	public class Solution {
	public static void main(String[] args) {
	/* Save input */
	Scanner scan = new Scanner(System.in);
	int size = scan.nextInt();
	int [] elements = new int[size];
	int [] weights = new int[size];
	for (int i = 0; i < size; i++) {
	elements[i] = scan.nextInt();
	}
	for (int i = 0; i < size; i++) {
	weights[i] = scan.nextInt();
	}
	scan.close();
	/* Calculate weighted mean */
	int total = 0;
	int totalWeights = 0;
	for (int i = 0; i < size; i++) {
	total += elements[i] * weights[i];
	totalWeights += weights[i];
	}
	double weightedMean = (double) total / totalWeights;
	System.out.format("%.1f", weightedMean);
	}
	}