DSA - 1 new - climbing stairs (DP)

70. Climbing Stairs — DP (Fibonacci pattern)

Insight — Problem follows Fibonacci recurrence; solve via recursion + memoization (store intermediate states in hashmap)

Comment — Recognized pattern only after manually enumerating paths; without that, the recurrence wasn’t obvious

Note

Whenever you see a problem where:

• You are moving toward a target
• Your move choices are fixed constants (e.g., 1, 2, 5)
• The order of moves matters

→ It almost always reduces to a linear recurrence relation (Fibonacci-like DP)