Find all distinct palindromic sub-strings of a given String in Python

Suppose we have a string with lowercase ASCII characters, we have to find all distinct continuous palindromic substrings of it.

So, if the input is like "bddaaa", then the output will be [a, aa, aaa, b, d, dd]

To solve this, we will follow these steps −

• m := a new map
• n := size of s
• matrix := make two rows of n number of 0s
• s := "@" concatenate s concatenate "#"
• for j in range 0 to 1, do
  • temp := 0
  • matrix[j, 0] := 0
  • i := 1
  • while i
  • while s[i - temp - 1] is same as s[i + j + temp], do
    • temp := temp + 1
  • matrix[j, i] := temp
  • k := 1
  • while (matrix[j, i - k] is not same as temp - k) and k
  • matrix[j,i+k] := minimum of matrix[j, i-k]
  • k := k + 1
• temp := maximum of temp - k, 0
• i := i + k

Example

Let us see the following implementation to get better understanding −

 Live Demo

def find_substr(s):
   m = dict()
   n = len(s)
   matrix = [[0 for x in range(n+1)] for x in range(2)]
   s = "@" + s + "#"
   for j in range(2):
      temp = 0
      matrix[j][0] = 0
      i = 1
      while i 
Input
bddaaa
Output
a
aa
b
aaa
d
dd