projecteuler.net/problem=14

014.py

#2016年10月8日 11:17:15 codegay
#https://projecteuler.net/problem=14


d = {}
for s in range(2,1000000):
    n = s
    c = 0
    while n >1:
        n = [n//2,3*n+1][n%2]
        c +=1

    d.update({s:c})


print(max(d.items(),key=lambda x: x[1]))

(837799, 524)
[Finished in 102.3s]