3084. Count Substrings Starting and Ending with Given Character

Medium

30 Points

Math

String

Counting

You are given a string s and a character c. Return the total number of substrings of s that start and end with c.

Examples

Example 1

Input: s = "abada", c = "a" Output: 6 Explanation: Substrings starting and ending with "a" are: " a bada" , " aba da" , " abada " , "ab a da" , "ab ada " , "abad a " .

Example 2

Input: s = "zzz", c = "z" Output: 6 Explanation: There are a total of 6 substrings in s and all start and end with "z" .

Constraints

1 <= s.length <= 105
s and c consist only of lowercase English letters.