I am solving Daily Codin Problem #7 with Python [Recurssion] Can anyone explain this code?

Question

Firstly I did it on my own by checking each string element and from a variable = 1 i plus 1 if the element were 1 or 2 (checking first if there werent 0s and in case of 2 the next element were less than 7) but it didnt work properly.

The code is from internet where i seek for answers and explanation but i dont get this recurssion.

Problem:
This problem was asked by Facebook.

Given the mapping a = 1, b = 2, ... z = 26, and an encoded message, count the number of ways it can be decoded.

For example, the message '111' would give 3, since it could be decoded as 'aaa', 'ka', and 'ak'.

You can assume that the messages are decodable. For example, '001' is not allowed.

https://code.sololearn.com/cYD13bYJ62EB/?ref=app

Answer 1

https://www.geeksforgeeks.org/count-possible-decodings-given-digit-sequence/

Hope this will help you understand...

Answer 2

Thanks Arun for the link above. I had already seen it but it doesnt make the code clear. I dont understand how the recursive adds up the number of possible decodings as there isn't '+1'...

Answer 3

Problem Statement:

Decode the logic and print the Pattern that corresponds to given input using c program.

If N = 3 then pattern will be:

10203010011012

4050809

****607

If N = 4 then pattern will be:

1020304017018019020

**50607014015016

****809012013

Constraints: Z <= N <= 100

Input Format

First line contains T, the number of test cases, each test case contains a single integer N

Output Format

First line print Case #i where i is the test case number, In the subsequent line, print thepattern

Sample Input

3

Sample Output

Case #1

10203010011012

**4050809

.*** 607

Case #2

1020304017018019020

**50607014015016

****809012013

Case #3

102030405026027028029030

**6070809022023024028****10011012019020021

******13014017018

***15016