Let's say take 2 strings, A and B, and define the similarity of the strings to be the length of the longest prefix common to both strings. For example, the similarity of strings `abc` and `abd` is 2, while the similarity of strings `aaa` and `aaab` is 3.
write a function that calculates the sum of similarities of a string S with each of it's **suffixes**.
```python
string_suffix('ababaa') => returns 11
string_suffix('abc') => returns 3
```
Explanation:
In the first case, the suffixes of the string are `ababaa`, `babaa`, `abaa`, `baa`, `aa` and `a`. The similarities of each of these strings with the string `ababaa` are 6,0,3,0,1,1 respectively. Thus the answer is 6 + 0 + 3 + 0 + 1 + 1 = 11.
For the second case, the answer is simply 3 + 0 + 0 = 3.
Note : Each string will have at least one character - no need to check for empty strings :)
string_suffix=lambda s:sum(s[:j-i]==s[i:j] for j in range(1,len(s)+1) for i in range(j))
string_suffix=lambda s:sum(s[:j-i]==s[i:j] for j in range(1,len(s)+1) for i in range(j))