/*
CSE 143, Summer 2012
Processes a map of exam scores removing people who failed the exam.
*/

import java.util.*;

public class ExamScores {
	public static void main (String[] args) {
		Map<String, Integer> m = new HashMap<String, Integer>();
		m.put("Allison", 42);
		m.put("Dane", 90);
		m.put("Victoria", 78); 
		m.put("Mikey", 70);
		m.put("Zack", 45);
		m.put("Charlie", 64);
		
		System.out.println(m);
		removeLessThanN(m, 50);
		System.out.println(m);
	}
	
	// removes all map entires with a value less than n
	public static void removeLessThanN (Map<String, Integer> m, int n) {
		// we have to create an iterator over the keySet not the map.
		// if we try to create an iterator over the map it does not know
		// whether we want its keys or values
		Iterator<String> itr = m.keySet().iterator();
		while (itr.hasNext()) {
			if (m.get(itr.next()) < n) {
				itr.remove();
			}
		}
	}
}