Facebook Hacker Cup Round 1: Labelmaker

labelmaker.py

ls, out = [line.strip() for line in open('input')], ''
for t in xrange(1, int(ls[0]) + 1): 
    st, n = ls[t].split(' ')
    n, k, l, p, r = int(n), len(st), 0, 1, ''
    while n >= p:
        n -= p
        p *= k
        l += 1
    for i in range(l):
        r += st[n % k]
        n /= k
    print "Case #{0}: {1}".format(t, r[::-1])