Using python to implement the tail recursion function-CodePudding

For a function p(0) = 10000, p(n) = p(n-1) 0.02*p(n-1),

the code should be like this:

def p(n,v=10000):
    if n == 0:
         return v
    else:
         return p(n-1,1.02*v)

But if p(0) = 10000, p(n) = p(n-1) 10**(n-1),

then how to write this tail recursion?

CodePudding user response：

This should solve your problem

def p(n):
    if n==0:
        return 10000
    else: # n!=0
        return p(n-1)   0.02 * p(n-1)
    
print(p(0)) # The result is 10000
print(p(1)) # The result is 10200.0

the first if will be the base of the recursion which is p(0) and the else will be the recursion function

CodePudding user response：

Well.. you already have tail recursion with the if n == 0: return v. You just need to rework the non constant return value. Try this:

def p(n, v=10000):
    if n == 0:
         return v
    else:
         return p(n - 1, v)   10**(n - 1)

CodePudding user response：

Here's the tali recursion code for the function that you wanted

def p(n,v=10000):
    if n == 0:
         return v
    else:
         return p(n-1, v   10**(n-1))

Here, we use the v as the value from the previous function recursion call, and then add the 10**(n-1) to it.