01. Count Real Numbers

package associativeArrays;

import java.util.Arrays;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;

public class P01CountRealNumbers {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        double[] numbersArr = Arrays
                .stream(scanner.nextLine().split(" "))
                .mapToDouble(Double::parseDouble)
                .toArray();

        TreeMap<Double, Integer> countMap = new TreeMap<>();

        for (double num : numbersArr) {
            if (!countMap.containsKey(num)) {
                countMap.put(num, 0);
            }

            countMap.put(num, countMap.get(num) + 1);
        }

        for (Map.Entry<Double, Integer> entry : countMap.entrySet()) {
            System.out.printf("%.0f -> %d%n", entry.getKey(), entry.getValue());
        }
    }
}