Create ClimbingStairs.js (#379)

* Create ClimbingStairs.js

* Update ClimbingStairs.js

Co-authored-by: vinayak <itssvinayak@gmail.com>

Dynamic-Programming/ClimbingStairs.js

@@ -0,0 +1,26 @@
+/*
+ * You are climbing a stair case. It takes n steps to reach to the top.
+ * Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
+*/
+
+const climbStairs = (n) => {
+  let prev = 0
+  let cur = 1
+  let temp
+
+  for (let i = 0; i < n; i++) {
+    temp = prev
+    prev = cur
+    cur += temp
+  }
+  return cur
+}
+
+const main = () => {
+  const number = 5
+
+  console.log('Number of ways to climb ' + number + ' stairs in ' + climbStairs(5))
+}
+
+// testing
+main()