// Helene Martin, CSE 143
// Sample midterm problems.

import java.util.*;

public class MidtermReview {
	public static void main(String[] args) {
		testDashed();
		System.out.println();
		testByAge();
	}

	// Write a recursive method called printDashed that takes an integer as a
	// parameter and that prints the integer with dashes in between the digits.
	//
	// printDashed(-834) -8-3-4
	// printDashed(6) 6
	// printDashed(-17) -1-7
	// printDashed(-4) -4
	// printDashed(983) 9-8-3
	// printDashed(42) 4-2
	// printDashed(0) 0
	// printDashed(29348) 2-9-3-4-8

	// Helpful extra cases to write out:
	// printDashed(342) 3- 4-2
	// printDashed(42) 4- 2
	// printDashed(2) 2
	public static void printDashed(int value) {
		if (value < 0) {
			System.out.print("-");
			printDashed(-value);
		} else if (value < 10) {
			System.out.print(value);
		} else {
			printDashed(value / 10); // "rest" of the number printed on the left
			System.out.print("-");
			printDashed(value % 10); // right-most digit printed on the right
		}
	}

	// return a new map with information about people with ages between the min
	// and max, inclusive. Each key is an integer age, and the value for that
	// key is a string with the names of all people at that age, separated by
	// "and" if there is more than one person of that age. Include only ages
	// between the min and max inclusive, where there is at least one person of
	// that age in the original map. If the map passed in is
	// empty, or if there are no people in the map between the min/max ages,
	// return an empty map.
	// in: {Paul=28, David=20, Janette=18, Marty=35, Stuart=98, Jessica=35,
	// Helene=40, Allison=18, Sara=15, Grace=25, Zack=20, Galen=15, Erik=20,
	// Tyler=6, Benson=48}
	// byAge(ages, 16, 25): {18=Janette and Allison, 20=David and Zack and Erik,
	// 25=Grace}
	public static Map<Integer, String> byAge(Map<String, Integer> ages,
			int min, int max) {
		Map<Integer, String> result = new HashMap<Integer, String>();

		for (String name : ages.keySet()) {
			int age = ages.get(name);
			if (min <= age && age <= max) {
				if (result.containsKey(age)) {
					result.put(age, result.get(age) + " and " + name);
				} else {
					result.put(age, name);
				}
			}
		}

		return result;
	}

	public static void testDashed() {
		printDashed(-834); // -8-3-4
		System.out.println();
		printDashed(6); // 6
		System.out.println();
		printDashed(-17); // -1-7
		System.out.println();
		printDashed(42); // 4-2
		System.out.println();
		printDashed(-4); // -4
		System.out.println();
		printDashed(983); // 9-8-3
		System.out.println();
		printDashed(0); // 0
		System.out.println();
		printDashed(29348); // 2-9-3-4-8
	}

	public static void testByAge() {
		Map<String, Integer> people = new HashMap<String, Integer>();
		people.put("Paul", 28);
		people.put("David", 20);
		people.put("Janette", 18);
		people.put("Marty", 35);
		people.put("Stuart", 98);
		people.put("Jessica", 35);
		people.put("Helene", 40);
		people.put("Allison", 18);
		people.put("Sara", 15);
		people.put("Grace", 25);
		people.put("Zack", 20);
		people.put("Galen", 15);
		people.put("Erik", 20);
		people.put("Tyler", 6);
		people.put("Benson", 48);

		Map<Integer, String> result = byAge(people, 16, 25);
		System.out.println(result);
	}
}