Recursion is like telling a story step by step—it’s clear and easy to understand. But when the story gets too long, it starts repeating itself, and that’s where DP comes in to save the day!
The key? Spot when your recursion is solving the same problem over and over. That’s called overlapping subproblems, and DP helps you store those results so you don’t waste time recalculating them.
Examples:
- Fibonacci: Naive recursion recalculates the same numbers, but DP stores them for reuse.
- 0/1 Knapsack: Recursion explores all possibilities, but DP optimizes by remembering past choices.
- Longest Increasing Subsequence (LIS): Recursion checks every path, but DP keeps track of the best one.
Pro Tip: If your recursion feels slow or you notice it’s solving the same thing repeatedly, it’s time to switch to DP!
Let’s Discuss:
- What was your “aha!” moment when you realized recursion could become DP?
- Do you prefer memoization (top-down) or tabulation (bottom-up)? Why?
- Share a problem where DP turned a slow solution into a fast one!
Hot take: “All DP problems start as recursion problems.” Do you agree? Let’s chat! 👇