Reading the post https://steemit.com/programming/@justyy/python-function-to-solve-the-chicken-and-rabbit-math-problem , I feeled the desire to try it in my favorite language.

Sor first, thank you @justyy for sharing initialy the solving of this litlle math game in Python.

Solving it first on a paper

If we had to solve it only with a pen and a paper with 2 rabbits and 1 chicken ? Let's try !

So with this approach I'm able to get back the initial statement of 2 rabbits and only 1 chicken

Now in Ocaml

let solve_rabbit_and_chicken heads legs = 
    let get_chicken_from rabbit = heads - rabbit in
    let rabbit = (legs - (2 * heads)) / 2 in
    let chicken = get_chicken_from rabbit in
    Some (rabbit,chicken)

The problem I have now is that I'm not sure the solution is always good. We can have negative values as an answer, or we can have incorrect parameters that's why I have used the Some constructor to return the value.

I need now to add code to detect the situation where there is a problem of consistency between legs and heads or in the result.

So the final code will be :

let solve_rabbit_and_chicken heads legs = 
    let get_chicken_from rabbit = heads - rabbit in
    if heads < 1 || legs < 2  || (legs mod 2 <> 0) then None else
    let rabbit = (legs - (2 * heads)) / 2 in
    let chicken = get_chicken_from rabbit in
    if rabbit < 0 || chicken < 0 then None else
    Some (rabbit,chicken)