1582 articles
Deep copy an undirected graph using DFS or BFS with a HashMap to track already-cloned nodes. Meta tests this to evaluate graph traversal, deep copy semantics, and cycle detection in recursive graph structures.
A complete cheatsheet of FAANG company-specific DSA problems, patterns, and optimal approaches. Use this as your final review before any Meta, Amazon, or Google coding interview.
The complete 1D Dynamic Programming roadmap for FAANG interviews — Fibonacci, House Robber, Kadane, Coin Change, LIS, Jump Game, Decode Ways, and Palindrome patterns with Python and JavaScript templates.
LC 70 Climbing Stairs is the canonical introduction to 1D dynamic programming. The recurrence dp[n] = dp[n-1] + dp[n-2] is pure Fibonacci, and mastering why it works — recursion to memoization to tabulation — unlocks the entire family of staircase DP problems asked at Google, Amazon, and Meta.
LC 746 Min Cost Climbing Stairs extends the Climbing Stairs Fibonacci DP with per-step costs. The recurrence dp[i] = cost[i] + min(dp[i-1], dp[i-2]) computes the minimum total cost to leave each step. Asked at Amazon and Google as a direct test of whether you can adapt a known recurrence pattern under new constraints.