week2: climbing-stairs

Author: reeseo3o

climbing-stairs/reeseo3o.js

@@ -0,0 +1,16 @@
+// 피보나치 수열 문제
+const climbStairs = (n) => {
+// f(n) = f(n-1) + f(n-2)
+    if (n <= 2) return n;
+
+    let prev2 = 1;
+    let prev1 = 2;
+
+    for (let i = 3; i <= n; i++) {
+        let current = prev1 + prev2; 
+        prev2 = prev1;
+        prev1 = current;
+    }
+
+    return prev1;
+};