I'm just in a funny mood. Don't take this post too seriously.

These are all of the problems I've solved using unordered_map. This should be a complete list. For context, I've solved maybe around 4000 problems in total?

• 1120C - Compress String
• Logistics from Estonian Open 2016

I think neither solution is intended. The moral of the story: this class (and unordered_set) are very rarely if ever necessary in competitive programming. Yes, in theory they can do in $$$O(1)$$$ what map does in $$$O(\log n)$$$. In practice, they have a pretty large constant and are maybe only marginally faster than map. And that's not to mention all the times you can get hacked on it.