Coding topo sort
Course Schedule I / II
LC 207, 210. Kahn vs DFS cycle. Return the order, not just true/false.
LC 207, 210. Kahn vs DFS cycle. Return the order, not just true/false.
LC 323. Union by rank + path compression. Count remaining roots.
LC 721. Email → parent. Then group names. Sort for the output contract.
Budgets, jitter, and why retries without a breaker take the site down.