From b36e23d095141ab75a173b7a52e666e6b21786a3 Mon Sep 17 00:00:00 2001
From: "codeflash-ai[bot]"
 <148906541+codeflash-ai[bot]@users.noreply.github.com>
Date: Sat, 17 Jan 2026 00:17:32 +0000
Subject: [PATCH] Optimize fibonacci

**Optimization Explanation:**
I replaced the naive exponential recursion with a memoized recursion using a Map to cache previously computed results. This preserves the original function signature and exact behavior (including handling of non-integer inputs) while reducing the runtime from O(phi^n) to O(k) where k is the number of distinct subproblems encountered. Using Map reduces repeated computations and memory churn without changing recursion depth or error characteristics.
---
 code_to_optimize_js/fibonacci.js | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/code_to_optimize_js/fibonacci.js b/code_to_optimize_js/fibonacci.js
index b0ab2b51c..701ad1c88 100644
--- a/code_to_optimize_js/fibonacci.js
+++ b/code_to_optimize_js/fibonacci.js
@@ -9,10 +9,20 @@
  * @returns {number} - The nth Fibonacci number
  */
 function fibonacci(n) {
-    if (n <= 1) {
-        return n;
+    const cache = new Map();
+    function fib(x) {
+        if (x <= 1) {
+            return x;
+        }
+        const cached = cache.get(x);
+        if (cached !== undefined) {
+            return cached;
+        }
+        const result = fib(x - 1) + fib(x - 2);
+        cache.set(x, result);
+        return result;
     }
-    return fibonacci(n - 1) + fibonacci(n - 2);
+    return fib(n);
 }
 
 /**