add solution: climbing-stairs

yihyun-kim1 · yihyun-kim1 · commit 14979c0363b0 · 2026-03-15T14:15:54.000+09:00
diff --git a/climbing-stairs/yihyun-kim1.js b/climbing-stairs/yihyun-kim1.js
@@ -0,0 +1,19 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+
+const climbStairs = (n) => {
+  if (n <= 2) return n;
+
+  let prev1 = 1;
+  let prev2 = 2;
+
+  for (let i = 3; i <= n; i++) {
+    const current = prev1 + prev2;
+    prev1 = prev2;
+    prev2 = current;
+  }
+
+  return prev2;
+};
