Topological ordering: detect whether dependency constraints can be satisfied

Topological ordering: There are n courses numbered 0 through n-1. Each [course, prerequisite] pair requires prerequisite first. Return whether all courses can be completed.

Input: A JSON object { "n": number, "prerequisites": [number, number][] }.

Output: A JSON boolean that is false exactly when the dependency graph contains a cycle.

Constraints:

0 <= n <= 100000
Every course id is in 0..n-1
Repeated prerequisite pairs are allowed

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

Difficulty: EASY. Variant: 19. Expect follow-up questions about complexity, edge cases, and alternative approaches.

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 prov

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.