solve: climbing stairs

Author: wogha95

climbing-stairs/wogha95.js

@@ -0,0 +1,20 @@
+// TC: O(N)
+// SC: O(1)
+
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var climbStairs = function (n) {
+  let previousStep = 0;
+  let currentStep = 1;
+
+  while (n > 0) {
+    n -= 1;
+    const nextStep = previousStep + currentStep;
+    previousStep = currentStep;
+    currentStep = nextStep;
+  }
+
+  return currentStep;
+};