Each lowercase English letter is mapped to a number as follows:

• 'a' and 'b' map to $1$

• 'c', 'd', and 'e' map to $2$

• 'f', 'g', and 'h' map to $3$

• 'i', 'j', and 'k' map to $4$

• 'l', 'm', and 'n' map to $5$

• 'o', 'p', and 'q' map to $6$

• 'r', 's', and 't' map to $7$

• 'u', 'v', and 'w' map to $8$

• 'x', 'y', and 'z' map to $9$

A substring is called divisible if the sum of the mapped values of its characters is divisible by the length of the substring.

Given a string word, return the number of divisible substrings in word.

Constraints:

• $1 \leq$ word.length $\leq 2000$

• word consists only of lowercase English letters.

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.