1358. Number of Substrings Containing All Three Characters

https://leetcode.com/problems/number-of-substrings-containing-all-three-characters

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.

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

Constraints:

• 3 <= s.length <= 5 x 10^4

• s only consists of a, b or ccharacters.

ac