Darbar 027 — Matrix Diagonal Sum

Easy

Darbar · Array

Catalog slot 27 of 548 (source id 271). Topic array / matrix.

Solve on LeetCode: Matrix Diagonal Sum. Do not treat this page as a statement dump.

Aligned T2T band: weeks 1–6. Start at Week 1. Full map: Darbar hub.

Pattern block: Timed routing (weeks 1-15, slots 1-120). Warmup: LeetCode-style easy problems (15 min each). Exam: Weekly timed block, 3-5 problems in 60 minutes.

Evidence (cookiecutter problem_027.md)

1. Attempt log (approaches that failed)
2. Final complexity (time and space)
3. One mistake corrected
4. Production concept this slot reinforces

Personal dates and the CSV tracker stay in the learner journal.

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Array index · Darbar hub

Darbar slot 27 of Tensor-to-Tenant · Previous · Next.