Desafíos 2014 - Semana 4

[sukoy]

Mucho mejor.

Código Python:

def max_cycle(a, b):
 
    cache = {1:1}
    
    def num(cache, n):
        if not n in cache:
            if n % 2:
                cache[n] = 1 + num(cache, 3 * n + 1)
            else:
                cache[n] = 1 + num(cache, n / 2)
        return cache[n]
 
    def sec(a, b):
        maxim = 0
        if a > b: a,b = b,a
        for i in xrange(a, b+1):
            tr = num(cache, i)
            if tr > maxim:
                maxim = tr
        return maxim
 
    return sec(a, b)
 
 
if __name__ == '__main__':
    from time import time
    t1 = time()
    assert max_cycle(1, 10) == 20
    assert max_cycle(100, 200) == 125
    assert max_cycle(201, 210) == 89
    assert max_cycle(900, 1000) == 174
    assert max_cycle(113383, 113383) == 248
    assert max_cycle(999999, 1) == 525
    assert max_cycle(20, 20) == 8
    assert max_cycle(9999, 9999) == 92
    assert max_cycle(1, 9999) == 262
    assert max_cycle(340, 3000) == 217
    assert max_cycle(3000, 340) == 217
    assert max_cycle(500, 101) == 144
    assert max_cycle(1, 1) == 1
    assert max_cycle(9999, 9998) == 92
    t2 = time()
    print "Tiempo de ejecucion %.3f s" % (t2 - t1)
#Tiempo de ejecucion 2.062 s
 

Saludos.