← Microsoft Interview Insights

Microsoft·Software Engineer·Technical Phone Screen·Intermediate

IntermediatePrefer not to say
Jun 2026

Summary

Microsoft coding interview, one question about navigating a matrix under certain constraints. Pretty standard algorithmic round, nothing too wild.

Questions Asked (1)

Q1

Given a matrix, find a path from a source cell to a destination cell that satisfies a set of constraints.

Algorithms & Data Structures
Author's notes

Classic grid traversal.

Create a free account to read the full note

AI HintsAI Generated

Suggested Approach

Clarify the constraints (e.g., obstacles, movement rules, cost) and then model the problem as a graph search. Choose BFS for unweighted shortest path or Dijkstra/A* for weighted, and discuss trade-offs like time/space complexity and optimality.

Pro tip: Always ask clarifying questions about edge cases (e.g., no path, source equals destination) and mention that you'd test with small matrices first. This shows attention to detail and prevents incorrect assumptions.

1. Clarify constraints and requirements

Ask about movement directions, obstacles, cost function, and whether the path must be shortest or just any valid path. Confirm input/output format and edge cases.

2. Choose the right algorithm

Based on constraints, select BFS for unweighted shortest path, Dijkstra for non-negative weights, or A* if a heuristic is available. For any path, DFS or BFS works.

3. Outline the algorithm

Describe the steps: initialize a queue/priority queue, track visited cells, and explore neighbors while checking constraints. For weighted, maintain distance array.

4. Analyze complexity and trade-offs

State time and space complexity (e.g., O(V+E) for BFS, O(E log V) for Dijkstra). Discuss when to use each and potential optimizations like bidirectional search.

5. Handle edge cases and test

Mention edge cases: source/destination out of bounds, no path, multiple paths, large matrices. Suggest testing with small examples and verifying correctness.

Key Points to Mention

  • Graph representation: cells as nodes, adjacent cells as edges
  • BFS for unweighted shortest path, Dijkstra for weighted, A* for heuristic
  • Visited set to avoid cycles and redundant work
  • Time and space complexity analysis
  • Edge cases: no path, source equals destination, obstacles
  • Trade-offs between algorithms and potential optimizations

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.