Getting KeyError in the following code to find “minimum number square to the number”

I am getting the error in the following code for the above stated problem using memoization please help me find the error and correct the code.

import sys
#sys.setrecursionlimit(10**5)
import math
cache={}
def m(n):
    if n==0:
        return 0

    ans=sys.maxsize
    root=int(math.sqrt(n))
    for i in range(1,root+1):

        nc=n-(i**2)
        if cache[nc] not in cache:
            sa=m(nc)
            cache[nc]=sa
            curr=1+sa

        else:
            curr=1+cache[nc]

        ans=min(ans,curr)

    return ans

    

print(m(int(input())))

Answer

It would help if you provided the full error output, which should include the line number and surrounding code. However, I suspect the issue lies in the following line:

if cache[nc] not in cache:

You’re checking whether the value of a dictionary key exists as a dictionary key. I assume you actually meant this (which will check whether a value is an existing dictionary key):

if nc not in cache: