LeetCode 190 ·
Easy
Reverse Bits
Reverse the bits of a 32-bit unsigned integer.
Try it
Step through the core mechanic. The simulator below runs the bit manipulation shape this problem is built on.
Walk the pattern
No dedicated step-through for this one yet. The shape is Bit manipulation — its pattern page has the interactive walkthrough, the reference implementation, and a five-problem progression that this problem sits inside.
The approach
Shift the result left and OR in the input's lowest bit, 32 times. Each step peels one bit off the input and pushes it to the mirrored position.
| Aspect | Value |
|---|---|
| Pattern | Bit manipulation |
| Recognise it by | Reverse the 32 bits of an integer. |
| Time complexity | O(1) |
| Space complexity | O(1) |
| Difficulty | Easy |
Who asks it
Companies known to ask this problem, from public LeetCode company-tag aggregations. A signal of where to expect it, not a guarantee.