1582 articles
Implement a FIFO queue using two stacks with amortized O(1) push and pop. The two-stack lazy-transfer trick is a FAANG interview staple that demonstrates deep understanding of amortized complexity and LIFO vs FIFO semantics.
Design a stack that supports push, pop, top, and getMin in O(1) time using a parallel min-tracking stack. A classic FAANG design interview problem testing stack invariants and auxiliary state maintenance.
Simulate a baseball scoring game using a stack to handle score records, doubles, sum operations, and cancellations in O(n) time. A clean stack-simulation problem that tests your ability to model stateful operations with LIFO access.
Compare two typed strings after applying backspace characters using a stack simulation or O(1) space two-pointer from the right. Covers both approaches with full complexity analysis and FAANG interview tips.
Find the minimum operations to return to the root folder by simulating file system navigation with a stack depth counter in O(n) time and O(1) space. A clean warm-up problem testing stack simulation and boundary conditions.