Plus Minus HackerRank Solution in Java | Programming Blog

Java Solution for HackerRank Plus Minus Problem

Given an array of integers, calculate the ratios of its elements that are positive, negative, and zero. Print the decimal value of each fraction on a new line with 6 places after the decimal.

Example 1 :

array = [1, 1, 0, -1, -1]

There are N = 5 elements, two positive, two negative and one zero. Their ratios are 2/5 = 0.400000, 2/5 = 0.400000 and 1/5 = 0.200000. Results are printed as: 

0.400000
0.400000
0.200000

1. proportion of positive values
2. proportion of negative values
3. proportion of zeros

Example 2 :

array = [-4, 3, -9, 0, 4, 1] 

There are 3 positive numbers, 2 negative numbers, and 1 zero in array. Following is answer :

3/6 = 0.500000
2/6 = 0.333333
1/6 = 0.166667

Lets see solution

Solution 1

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;

class Result {

    public static void plusMinus(List<Integer> array) {
   
        double positive = 0, negative = 0, zero = 0;
        int arraySize = array.size();
        
        for (int i = 0; i < array.size(); i++) {
            
            if (array.get(i) > 0) {
                positive++;
            } else if (array.get(i) < 0) {
                negative++;
            } else {
                zero++;
            }
        }
        
        System.out.println(positive / arraySize);
        System.out.println(negative / arraySize);
        System.out.println(zero / arraySize);

    }

}

public class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(
            new InputStreamReader(System.in));

        int n = Integer.parseInt(bufferedReader.readLine().trim());

        List<Integer> arr = Stream.of(bufferedReader.readLine()
            .replaceAll("\\s+$", "").split(" "))
            .map(Integer::parseInt)
            .collect(toList());

        Result.plusMinus(arr);

        bufferedReader.close();
    }
}

Solution Explanation :

• Define 3 double variables, and initialize with 0 value.
• Traverse through given list and find all positive, negative and zero numbers and increment positive, negative and zero variables value respectively.
• Now divide all 3 values with list size.

 

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