climbing-stairs solution

Author: jdy8739

climbing-stairs/jdy8739.js

@@ -0,0 +1,20 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var climbStairs = function(n) {
+    let first = 1;
+    let second = 2;
+
+    if (n <= 2) {
+        return n;
+    }
+
+    for (let i=2; i<n; i++) {
+        let tmp = second;
+        second = first + second;
+        first = tmp;
+    }
+
+    return second;
+};