add chapter 11

Author: loiane

chapter11/01-Recursion.js

@@ -0,0 +1,20 @@
+function fibonacci(num){
+    if (num === 1 || num === 2){
+        return 1;
+    }
+    if (num > 2){
+        return fibonacci(num - 1) + fibonacci(num - 2);
+    }
+}
+
+function fib(num){
+    var n1 = 1,
+        n2 = 1,
+        n = 1;
+    for (var i = 3; i<=num; i++){
+        n = n1 + n2;
+        n1 = n2;
+        n2 = n;
+    }
+    return n;
+}