# Program to count number of distinct substrings in s in Python

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Suppose we have a string s, we have to find the number of distinct non-empty substrings of s.

So, if the input is like s = "abaa", then the output will be 8 because, the substrings are ["a", "b", "ab", "ba", "aa", "aba", "baa", "abaa"].

To solve this, we will follow these steps −

• trie := a new map
• n := size of s
• for i in range 0 to n - 1, do
• curr := trie
• for j in range i to n - 1, do
• c := s[j]
• if c not in curr, then
• curr[c] := a new map
• curr := curr[c]
• curr["*"] := True
• q := make a queue, and insert trie
• ans := 0
• while q is non-empty, do
• ans := ans + 1
• t := left item of q, and delete this item from q
• for each c in t, do
• if c is not same as "*", then
• insert t[c] at the end of q
• return ans - 1

## Example

Let us see the following implementation to get better understanding −

from collections import deque
def solve(s):
trie = {}
n = len(s)
for i in range(n):
curr = trie
for j in range(i, n):
c = s[j]
if c not in curr:
curr[c] = {}
curr = curr[c]
curr["*"] = True

q = deque([trie])
ans = 0
while q:
ans += 1
t = q.popleft()
for c in t:
if c != "*":
q.append(t[c])
return ans - 1

s = "abaa"
print(solve(s))

## Input

"abaa"

## Output

8
Updated on 18-Oct-2021 12:20:18