Problems from 2021 ICPC North America Regionals (February 26 2022)

Languages
Bracket Pairing0.0036449615631%6.3Harden
Code Guessing0.00140259759623%2.9Mediumen
Concert Rehearsal0.027526478713%7.7Harden
Espresso!0.0068185968037%2.3Easyen
Even Substrings0.5616743039531%6.4Harden
Land Equality0.0035591018020%5.4Mediumen
Lone Rook0.0314645128717%7.3Harden
Parking Lot0.0510852125727%6.4Harden
Stream Lag0.006679039750%3.1Mediumen
Subprime0.019266423836%4.0Mediumen
Tree Number Generator0.5315633359227%7.5Harden
Ultimate Binary Watch0.00792588104040%1.8Easyen
Word Puzzle0.2345535911833%4.9Mediumen