Create nth-fibonacci.js

Author: varun93

nth-fibonacci.js

@@ -0,0 +1,35 @@
+const fiboRecursive = n => {
+  if (n < 2) {
+    return n;
+  } else {
+    return fiboRecursive(n - 1) + fiboRecursive(n - 2);
+  }
+};
+
+const fibo = n => {
+  const array = [];
+  let i = 2;
+  array.push(0);
+  array.push(1);
+  while (i < n) {
+    array.push(array[i - 1] + array[i - 2]);
+    i++;
+  }
+  return array[i - 1];
+};
+
+const spaceOptimizedFibo = n => {
+  let a = 0,
+    b = 1,
+    c,
+    i = 3;
+
+  while (i <= n) {
+    c = a + b;
+    a = b;
+    b = c;
+    ++i;
+  }
+
+  return c;
+};