Count Equal and Divisible Pairs in an Array - Solution & Explanation

This approach involves iterating over all possible pairs (i, j) using nested loops and checking if the conditions are met.

This code iterates over all pairs (i, j) where 0 <= i < j < n and checks if the elements are equal and i*j is divisible by k. The counter increment occurs whenever both conditions are satisfied.

Use a hashmap to count occurrences of elements. Check each pair using a single loop by jumping indices where same elements exist. This reduces the number of checks as repeated pairs can be calculated mathematically.

The C solution doesn't fully utilize the given approach of frequency counting, but similarly iterates through the pair calculations since hashmap isn't directly usable in C standard library.