solve 70

Author: mumunuu

climbing-stairs/mumunuu.java

@@ -0,0 +1,23 @@
+// 70. Climbing Stairs https://leetcode.com/problems/climbing-stairs/description/
+class Solution {
+    public int climbStairs(int n) {
+
+
+        if (n <= 2) {
+            return n;
+        }
+
+        int a = 1;
+        int b = 2;
+
+        for (int i = 3; i <= n; i++) {
+            int temp = b;
+            b = a + b;
+            a = temp;
+        }
+
+        return b;
+
+
+    }
+}