Design Memory Allocator
Also known as: Design Memory Allocator (Custom)
Design a memory allocator - like how an OS manages RAM! Memory is an array of n units. 0 means free, non-zero means allocated. allocate(size, m_id): Find first contiguous free block, mark with m_id query(): Return total allocated units Example: allocate(3, 1) → 0, query() → 3
This one rewards writing clear, step-by-step logic you can trust. Interviewers love it because it reveals your step-by-step correctness and your edge-case discipline. The classic mistake is a tiny ordering detail; write it like you're debugging a state machine.
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