Problem 1253 --The 3n + 1 problem

1253: The 3n + 1 problem

上一题 正确率: $79.66\%$ 下一题
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Time Limit $1$ 秒/Second(s) Memory Limit $512$ 兆字节/Megabyte(s)
提交总数 $236$ 正确数量 $188$
裁判形式 标准裁判/Standard Judge 我的状态 尚未尝试
难度 分类标签 模拟

Description

Problems in Computer Science are often classified as belonging to a certain class of problems (e.g., NP, Unsolvable, Recursive). In this problem you will be analyzing a property of an algorithm whose classification is not known for all possible inputs.

Consider the following algorithm:


1. input n

2. print n

3. if n = 1 then STOP

4. if n is odd then n <- 3n + 1

5. else n <- n / 2

6. GOTO 2


Given the input 22, the following sequence of numbers will be printed 22 11 34 17 52 26 13 40 20 10 5 16 8 4 2 1

It is conjectured that the algorithm above will terminate (when a 1 is printed) for any integral input value. Despite the simplicity of the algorithm, it is unknown whether this conjecture is true. It has been verified, however, for all integers n such that 0 < n < 1,000,000 (and, in fact, for many more numbers than this.)

Given an input n, it is possible to determine the number of numbers printed (including the 1). For a given n this is called the cycle-length of n. In the example above, the cycle length of 22 is 16.

For any two numbers i and j you are to determine the maximum cycle length over all numbers between i and j.

Input

The input will consist of a series of pairs of integers i and j, one pair of integers per line. All integers will be less than 1,000,000 and greater than 0.

You should process all pairs of integers and for each pair determine the maximum cycle length over all integers between and including i and j.

You can assume that no opperation overflows a 32-bit integer.

Output

For each pair of input integers i and j you should output i, j, and the maximum cycle length for integers between and including i and j. These three numbers should be separated by at least one space with all three numbers on one line and with one line of output for each line of input. The integers i and j must appear in the output in the same order in which they appeared in the input and should be followed by the maximum cycle length (on the same line).

Sample Input复制

1 10
100 200
201 210
900 1000

Sample Output复制

1 10 20
100 200 125
201 210 89
900 1000 174

提示

wq

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本题记录 用 户（点击查看用户） 运行号（点击购买题解） 时 间
算法最快[$0 $ms] 千年孤独 569339 2020-03-02 22:09:27
内存最少[$0 $KB] 蔡列庆 473886 2019-09-25 19:44:29
第一AC 邓炜@信息与计算科学142 4387 2016-05-28 11:17:09
第一挑战 邓炜@信息与计算科学142 4387 2016-05-28 11:17:09

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竞赛编号 竞赛名称 竞赛时间 访问比赛
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1383 2019-2020-1学期《Java编程技术》:循环结构【17电子信息工程123班】 2019-09-20 11:00:00 请登录