feat: add climbing stairs solution

Author: mangodm-web

climbing-stairs/mangodm-web.py

@@ -0,0 +1,9 @@
+class Solution:
+    def climbStairs(self, n: int) -> int:
+        dp = [0] * (n + 1)
+        dp[0], dp[1] = 1, 1
+
+        for i in range(2, n + 1):
+            dp[i] = dp[i - 1] + dp[i - 2]
+
+        return dp[n]