distinct_echo_substrings.py

'''
Return the number of distinct non-empty substrings of text that can be written as the concatenation of some string with itself (i.e. it can be written as a + a where a is some string).
'''

class Solution:
    def distinctEchoSubstrings(self, text: str) -> int:
        res = set()
        n = len(text)
        def check(s):
            l = len(s)
            if l % 2 == 0 and s[:l//2] == s[l//2:]:
                return True
            return False
        for i in range(n):
            for j in range(i+1, n+1):
                if check(text[i:j]):
                    res.add(text[i:j])
        #print(res)
        return len(res)