Thanks, I cleared all the test cases! Takeaways from my solution:

• I used two maps, one to keep count and one to track the number of potential triplets.
• Keeping track of the latter makes updating the result trivial.
• Only a single pass of the array was needed.
• No edge case condition when R is 1.

I highly recommend to anyone not quite understanding, think through the case

5 2
1 2 1 2 4

The expected answer is 3. I was getting 4 with my initial approach. Good luck!