Update Climbing_Stairs.py

Author: Seyda1

Climbing_Stairs/Climbing_Stairs.py

@@ -1 +1,24 @@
+class Solution(object):
+    def climbStairs(self, n):
+        """
+        Given a number n, return the number of distinct ways to climb to the top of a staircase with n steps.
+        
+        :type n: int
+        :rtype: int
+        """
+        if n == 1:
+            return 1
+        elif n == 2:
+            return 2
 
+        prev1 = 1  # Base case: the number of ways to reach the first step
+        prev2 = 2  # Base case: the number of ways to reach the second step
+        current = 0
+
+        # Start from step 3 and calculate the number of ways to reach each subsequent step
+        for i in range(3, n + 1):
+            current = prev1 + prev2  # The number of ways to reach the current step is the sum of the previous two
+            prev1 = prev2  # Update prev1 to be the previous step
+            prev2 = current  # Update prev2 to be the current step
+
+        return current