I am trying to encode a int list to a unique number using following logic
b=28
l=[6, 4, 23, 28, 26, 9, 7, 16, 2]
sum=0
for i,n in enumerate(l):
sum+=(28**i)*n
This generates a huge number. how can i get back the original list from this number? I have tried the following code
result=[]
while sum!=0:
n=sum%28
result.append(n)
sum=sum//28
print(result)
However the result prints [6, 4, 23, 0, 27, 9, 7, 16, 2]
Your encoding method is basically a base-28 conversion and can only allow integers no greater than 27; otherwise it would carry over to the next number, as evident by your decoded sequence, where 28 becomes 0 and the next number, 26, becomes 27. There's no fix for your code. You just have to come up with a new encoding algorithm if you want to be able to accommodate numbers greater than 27.
The way you encode the list is similar to converting a base-28 number to decimal number. Since the largest number in the list is 28 itself, it is proper to encode the list with base-29 i.e (Largest_number+1). So you can use the following code to encode.
l=[6, 4, 23, 28, 27, 9, 7, 16, 2]
b=max(l)+1
sum=0
for i,n in enumerate(l):
sum+=(b**i)*n
and for decoding,
result=[]
while sum!=0:
n=sum%b
result.append(n)
sum=sum//b
print(result)
