Create 509-fibonacci-number.js

Author: everthis

509-fibonacci-number.js

@@ -0,0 +1,13 @@
+/**
+ * @param {number} N
+ * @return {number}
+ */
+const cache = {}
+const fib = function(N) {
+  if(cache[N]) return cache[N]
+  if(N === 0) return 0
+  if(N === 1) return 1
+  let res = fib(N - 1) + fib(N - 2)
+  cache[N] = res
+  return res
+};