CitiesByContinentAndCountry_06/JavaAdvanced

package JavaProModule.JavaAdvanced.SetsAndMapsLab;

import java.util.*;
import java.util.stream.Collectors;

public class CitiesByContinentAndCountry_06 {
    public static void main(String[] args) {
        Scanner read = new Scanner(System.in);

        Map<String,Map<String,List<String>>> data = new LinkedHashMap<>();
        // we have Continent,Country,City

        int loop = Integer.parseInt(read.nextLine());

        for (int index = 0; index < loop; index++) {
            String [] input = read.nextLine().split("\\s+");
            String continent = input[0];
            String country = input[1];
            String city = input[2];

            data.putIfAbsent(continent,new LinkedHashMap<>());
            data.get(continent).putIfAbsent(country,new ArrayList<>());
            data.get(continent).get(country).add(city);

        }
        data.forEach((key,value) -> {
            System.out.println(key + ":");
            value.forEach((innerKey,innerValue) -> {
                System.out.println(" " + innerKey + " -> " + String.join(", ",innerValue));
            });
        });
/* for (Map.Entry<String, Map<String, List<String>>> entry : data.entrySet()) {
            String key = entry.getKey();
            Map<String, List<String>> value = entry.getValue();
            System.out.println(key + ":");
            value.forEach((innerKey, innerValue) -> {
                System.out.println(" " + innerKey + " -> " + String.join(", ", innerValue));
            });
        } for (Map.Entry<String, List<String>> entry : value.entrySet()) {
                String innerKey = entry.getKey();
                List<String> innerValue = entry.getValue();
                System.out.println(" " + innerKey + " -> " + String.join(", ", innerValue));
            }*/


    }
}