1593. Split a String Into the Max Number of Unique Substrings.py

'''
Given a string s, return the maximum number of unique substrings that the given string can be split into.

You can split string s into any list of non-empty substrings, where the concatenation of the substrings forms the original string. However, you must split the substrings such that all of them are unique.

A substring is a contiguous sequence of characters within a string.

 

Example 1:

Input: s = "ababccc"
Output: 5
Explanation: One way to split maximally is ['a', 'b', 'ab', 'c', 'cc']. Splitting like ['a', 'b', 'a', 'b', 'c', 'cc'] is not valid as you have 'a' and 'b' multiple times.
Example 2:

Input: s = "aba"
Output: 2
Explanation: One way to split maximally is ['a', 'ba'].
Example 3:

Input: s = "aa"
Output: 1
Explanation: It is impossible to split the string any further.
 

Constraints:

1 <= s.length <= 16

s contains only lower case English letters.
'''

global maxi
class Solution:
    def maxUniqueSplit(self, s):
        global maxi
        maxi = 0
        recursion(s, 0, [])
        return maxi


def recursion(s, i, ans):
    global maxi
    if i>=len(s):
        maxi = max(maxi, len(ans))

    l = 0
    while(i+l<len(s)):
        temp = s[i:i+l+1]
        if temp not in ans:
            recursion(s, i+l+1, ans+[temp])
        l+=1