Don't be ashamed of N^2 II
Medium-level problem but given the small constraints it becomes actually easy with an N^2 approach (N=2000). Find all the substrings and in the process use a mapping to calculate the sum, then check the sum%length condition. Code is down below, cheers, ACC. Number of Divisible Substrings - LeetCode 2950. Number of Divisible Substrings Medium 1 0 Add to List Share Each character of the English alphabet has been mapped to a digit as shown below. A string is divisible if the sum of the mapped values of its characters is divisible by its length. Given a string s , return the number of divisible substrings of s . A substring is a contiguous non-empty sequence of characters within a string. Example 1: Substring Mapped Sum Length Divisible? a 1 1 1 Yes s 7 7 1 Yes d 2 2 1 Yes f 3 3 1 Yes as 1, 7 8 2 Yes sd 7, 2 9 2 No df 2, 3 5 2 No asd 1, 7, 2 10 3 No sdf 7, 2, 3 12 3 Yes asdf 1, 7, 2, 3 13 4 No Input: word = "asdf" Output: ...