http://googledevjp.blogspot.com/2011/04/google-code-jam-2011.html

bt.py

#http://googledevjp.blogspot.com/2011/04/google-code-jam-2011.html

def solve(rest, bords, counts):
    if bords == []:
        return rest == 0
    bord  = bords[-1]
    count = rest / bord
    rest  = rest % bord
    while count >= 0:
        if solve(rest, bords[0:-1], counts):
            counts.append(count)
            return True
        count -= 1
        rest += bord
    return False

def solver(length, bords, counts):
    if solve(length, bords, counts):
        answer = " + ".join(["%d*%d" % tuple(x) for x in zip(counts, bords)])
        print(answer + " = " + str(eval(answer)))
        print("Boards must have at least %d." % reduce(lambda x,y:x+y, counts))

if __name__ == "__main__":
    length = 10**10
    bords = sorted([233,456,787])
    counts = list()
    solver(length, bords, counts)
    # big(?) scale problem :) 500 bords(about ten thousands meters)
    import random
    bords = set()
    while len(bords) != 500:
        bords.add(int((100000-1)*random.random())+1)
    bords = sorted(list(bords))
    counts = list()
    solver(length, bords, counts)