How would you create a code that raises a number to the power of another number?

Question

Without using ** ((thanks for the correction))
Input 1= base number
Input 2= exponent
...
I tried by using functions but I don't really know

Answer 1

FYI, the power operator in python is **, not ^^.

Here is an example using the square-and-multiply method:

def myPow(n, e):
if e == 0:
return 1
if e == 1:
return n
if e % 2 == 0:
return myPow(n*n, e/2)
else:
return myPow(n*n, (e-1)/2) * n

print("Exponentiation")
n = input("Please enter the base number: ")
print(n)
e = input("Please enter the exponent: ")
print(e)
print(n + "**" + e + " = " + str(myPow(int(n), int(e))))

Answer 2

If you understand the other recursion call, you should understand this one too.

Here is an example of use of the square-and-multiply method. Each line corresponds to a different level of recursion.
3**13
= ((3*3)**((13-1)/2))*3 = (9**6)*3
= ((9*9)**(6/2))*2 = (81**3)*2
= ((81*81)**((3-1)/2))*81*3 = (6561**1)*81*3 (exponent is 1, the recursion starts to bubble up)
= 6561*81*3
= 531441*3
= 1594323

Instead of doing 12 multiplications (3*3*3*...*3), we did only 5 multiplications (3*3, 9*9, 81*81, 6561*81, 531441*3). And dividing by 2 is as trivial for a computer as it is for us to divide by 10.

Answer 3

Awesome! It's really amazing to see how a short code can do that. However, I don't understand the last line of the function : return myPow(n*n, (e-1)/2) * n

Answer 4

Thank you very much!

Answer 5

print(2**3)
->8

Two * are used for raising something to the power of another.