우박 수열

3n_1.py

import functools
import sys

@functools.lru_cache(maxsize=None) # Python 3.2+
def f(n):
    if n == 1:
        return 1
    elif n % 2 == 0:
        return 1 + f(n // 2)
    else:
        return 1 + f(n * 3 + 1)

def solve(i, j):
    return max(map(f, range(i, j+1)))

for line in sys.stdin:
    i, j = map(int, line.split())
    print(i, j, solve(i, j))