Problem 52422. 3n + 1 Problem (a.k.a The Collatz Conjecture)

The 3n + 1 problem (a.k.a The Collatz Conjecture)
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
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.
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 greater than 0.
Output
For each pair of input integers i and j, output a vector with 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.
% Sample Input Sample Output
% 1 10 [1, 10, 20]
% 100 200 [100, 200, 125]
% 201 210 [201, 210, 89]
% 900 1000 [900, 1000, 174]
Solve

Solution Stats

72.73% Correct | 27.27% Incorrect
Last Solution submitted on Jul 16, 2024

Problem Comments

Solution Comments

Show comments

Problem Recent Solvers30

Suggested Problems

Problem Tags

collatz vector

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!