Find the minimum number of steps from the source to the destination.

Start by restating the contract for Find the minimum number of steps from the source to the destination. and explicitly clarify any difference between this candidate-reported label and the desired input/output behavior. Choose the representation that makes the central invariant visible: after each operation, state what is known to be correct and why it remains true. Begin with a simple baseline if it helps establish correctness, then replace its bottleneck with the appropriate data structure or recurrence. Walk through a small edge-case example aloud, including empty or minimal input, repeated values where relevant, and boundary indexes. Do not invent missing constraints: name the assumption and ask for confirmation. The final implementation should account for every stored state when reporting time and space complexity, not just the outer loop. This produces a useful prep answer even when the scraped source has incomplete wording. Complexity: the running sum reaches |target| after O(sqrt(|target|)) steps, with O(1) time per step and O(1) space.