def makeTheVectors (subjects):
    subjectNames = subjects.keys()
    workvector = []
    valuevector = []
    subjectDic = {}
    subnumber = 0
    for subject in subjectNames:
        subjectDic[subnumber] = subject
        subnumber += 1
    for subject in subjects.values():
        workvector.append(subject[1])
        valuevector.append(subject[0])
    return subjectDic, valuevector, workvector

def maximumList1 (subjects, maxWork):
    x = {}
    subjectDic, v, w = makeTheVectors(subjects)
    i = len(v) - 1
    subjectsToTake = {}
    print "Value vector:",v
    print "Work  vector:",w
    print "initial i =",i
    print "___________________"
    print
    maxValue, subjectVector = maximumList0 (i, x, v, w, maxWork)
    print "Maximum possible class value =",maxValue
    print subjectVector

def maximumList0 (i, x, v, w, maxWork):
    """Returns a vector of subjects and the value resulting from that vector."""
    print "i=",i
    if i == 0:#then we're at the end of the list.
        if w[i] < maxWork:#then we take it.
            x[i] = 1
            return v[i], x
        else:#then we don't take it.
            x[i] = 0
            return 0, x
    #defining the don't take branch:
    without_i, x = maximumList0 (i-1, x, v, w, maxWork)
    if w[i] > maxWork:#then we can't add this one, nor proceed any further down the take branch.
        x[i] = 0
        return without_i, x
    else:#we choose between the take and don't take branches.
        with_i, x = maximumList0 (i-1, x, v, w, maxWork-w[i])
        with_i += v[i]#this is the value of our take branch.
    if with_i > without_i:#then the "take" branch is better, so we take i.
        x[i] = 1
        return with_i, x
    else:#then the "don't take" branch is better, so we don't take i.
        x[i] = 0
        return without_i, x