El concepto de función recursiva siempre me sorprende lo mal que se explica.
Y me sorprende lo mal que la mayoría de alumnos lo entiende.
Porque si has explicado lo que es una función y como se evalúa, no tiene ningún tipo de confusión.
https://mitpress.mit.edu/sites/default/files/sicp/full-text/sicp/book/node15.html
From one point of view, they seem hardly different at all. Both compute the same mathematical function on the same domain, and each requires a number of steps proportional to n to compute n!. Indeed, both processes even carry out the same sequence of multiplications, obtaining the same sequence of partial products. On the other hand, when we consider the ``shapes'' of the two processes, we find that they evolve quite differently.
Consider the first process. The substitution model reveals a shape of expansion followed by contraction, indicated by the arrow in figure [*]. The expansion occurs as the process builds up a chain of deferred operations (in this case, a chain of multiplications). The contraction occurs as the operations are actually performed. This type of process, characterized by a chain of deferred operations, is called a recursive process. Carrying out this process requires that the interpreter keep track of the operations to be performed later on. In the computation of n!, the length of the chain of deferred multiplications, and hence the amount of information needed to keep track of it, grows linearly with n (is proportional to n), just like the number of steps. Such a process is called a linear recursive process.
By contrast, the second process does not grow and shrink. At each step, all we need to keep track of, for any n, are the current values of the variables product, counter, and max-count. We call this an iterative process. In general, an iterative process is one whose state can be summarized by a fixed number of state variables, together with a fixed rule that describes how the state variables should be updated as the process moves from state to state and an (optional) end test that specifies conditions under which the process should terminate. In computing n!, the number of steps required grows linearly with n. Such a process is called a linear iterative process.
De hecho si nos quedamos con esta frase del proceso lineal iterativo.
In general, an iterative process is one whose state can be summarized by a fixed number of state variables, together with a fixed rule that describes how the state variables should be updated as the process moves from state to state and an (optional) end test that specifies conditions under which the process should terminate.
Vemos que todos los procesos lineal recursivos se pueden expresar como lineal iterativos... y viceversa.
De hecho no doy por valida la distinción del SICP en que distingue entre el stack interprete y tu stack...
Pero bueno, prefiero el SICP a decir que una funcion recursiva es una funcion que se invoca cada vez con menos parametros...
func factorial(a, b, c, d) {
return factorial(a, b, c)
// despues llamas factorial(a,b)
// despues factorial(a)
}
??? no entendi la verdad, y eso que ha definido parametros justo encima kekekek
