85 years old (Born on October 09, 1939)
Happy Birthday, John Hopcroft! May your day be filled with fewer computational complexities and more cake-filled algorithms. Your groundbreaking work in the theory of computation has inspired countless minds—though we're still trying to figure out if there's an efficient algorithm for counting all those candles on your birthday cake!Congratulations again on receiving the prestigious Turing Award; clearly you've mastered life's data structures better than most people master their grocery lists. Here's wishing you another year full of laughter, joy, and minimal runtime errors as you continue inspiring generations through brilliant insights (and perhaps a few good jokes along the way). Happy computing—and happy celebrating!