mongouniversity-hw-3.1.js

var MongoClient = require('mongodb').MongoClient;

MongoClient.connect('mongodb://localhost:27017/school', function(err, db) {
	if(err) throw err;

	var cursor = db.collection('students').find().sort({'name': -1, 'scores': -1});

	cursor.each(function(err, doc) {
        	if(err) throw err;

        	if(doc == null) {
        	    return db.close();
        	}
		var scores = doc.scores;
		var tempScore = false;
		for (var key in scores) {
			if (scores[key].type == 'homework') { 
				if (! tempScore) {
					tempScore = scores[key];
				} else {
					if (tempScore.score <= scores[key].score) {
						// remove temp score
						db.collection('students').update({_id: doc._id}, {$pull: {scores: tempScore}});
						// set new temp score
						tempScore = scores[key];
					} else {
						// remove current score
						db.collection('students').update({_id: doc._id}, {$pull: {scores: scores[key]}});
					}
				}
			}
		}
	});
});