Description
Given a string s
 consisting only of characters a, b and c.
Return the number of substrings containing at least one occurrence of all these characters a, b and c.
Â
Example 1:
Input: s = "abcabc" Output: 10 Explanation: The substrings containing at least one occurrence of the characters a, b and c are "abc", "abca", "abcab", "abcabc", "bca", "bcab", "bcabc", "cab", "cabc" and "abc" (again).
Example 2:
Input: s = "aaacb" Output: 3 Explanation: The substrings containing at least one occurrence of the characters a, b and c are "aaacb", "aacb" and "acb".
Example 3:
Input: s = "abc" Output: 1
Â
Constraints:
3 <= s.length <= 5 x 10^4
s
 only consists of a, b or c characters.
Solution
Python3
class Solution:
def numberOfSubstrings(self, s: str) -> int:
mp = {c:0 for c in "abc"}
res = i = 0
for j, c in enumerate(s):
mp[c] += 1
while all(mp.values()):
mp[s[i]] -= 1
i += 1
res += i
return res