You are given an integer array nums.

A distinct value $x$ is called special if it satisfies both of the following conditions:

• It appears at least $3$ times in nums.

• The difference between every pair of consecutive indices where $x$ appears is equal (the occurrence indices form an arithmetic sequence).

Return the number of distinct special values in nums.

Constraints:

• $3 \leq$ nums.length $\leq 10^5$

• $1 \leq$ nums[i] $\leq 10^9$

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.