Coding (Algo)

Matrix boundary traversal: shrink four boundaries while visiting every matrix cell exactly once

Matrix boundary traversal: Return all values of a rectangular matrix in clockwise spiral order starting at the top-left corner.

Input: A JSON object { "matrix": number[][] }.

Output: A JSON number[] containing every matrix value exactly once.

Constraints:

0 <= matrix.length <= 1000
All non-empty rows have the same length
The output size equals rows multiplied by columns

Read one JSON value from stdin and print exactly one JSON-serialized answer to stdout with no extra text.

Difficulty: EASY. Variant: 22. Balance correctness, maintainability, and clear review-ready code.

Practice context

This coding (algo) exercise trains prompt interpretation, explicit assumptions, a concrete response, and a concise explanation of the decisions made. It is marked easy difficulty.

The signed-in workspace provides the tools required by the round, such as recording, code execution, diagrams

What this task practices

This coding (algo) exercise trains the same sequence expected in an interview: understand the prompt, make assumptions explicit, produce a concrete answer, and explain the decisions behind it. The task is marked easy difficulty. The private workspace adds the tools required by this round, such as recording, code execution, diagrams, evidence panels, or structured notes. It also preserves the attempt so later feedback can be compared with previous work. Evaluation is based on task-specific criteria and the candidate seniority selected in the preparation path. Public pages never expose the reference solution, hidden tests, evaluator instructions, or another candidate’s work.