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#F0487. The 3n + 1 problem

    ID: 493 传统题 1000ms 64MiB 尝试: 0 已通过: 0 难度: (无) 上传者: 标签>待分类整理状态难度待定难度共享题库高校与竞赛共享题英文题面题目来源题面语言

The 3n + 1 problem

题目描述

Consider the following algorithm to generate a sequence of numbers. Start with an integer n. If n is even, divide by 2. If n is odd, multiply by 3 and add 1. Repeat this process with the new value of n, terminating when n = 1. For example, the following sequence of numbers will be generated for n = 22: 22 11 34 17 52 26 13 40 20 10 5 16 8 4 2 1 It is conjectured (but not yet proven) that this algorithm will terminate at n = 1 for every integer n. Still, the conjecture holds for all integers up to at least 1, 000, 000. For an input n, the cycle-length of n is the number of numbers generated up to and including the 1. In the example above, the cycle length of 22 is 16. Given any two numbers i and j, you are to determine the maximum cycle length over all numbers between i and j, including both endpoints.

输入格式

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.

输出格式

For each pair of input integers i and j, output i, j in the same order in which they appeared in the input and then the maximum cycle length for integers between and including i and j. These three numbers should be separated by one space, with all three numbers on one line and with one line of output for each line of input.

样例 1

输入

1 10
100 200
201 210
900 1000

输出

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

提示

杭电1032

题目来源:fps-xiao-1001-1015.xml;FPS 共享题包,题包内第 13 题。保留原作者与原赛事署名。