Update 070.py

Author: chandansgowda

001-500/070.py

@@ -4,3 +4,11 @@ def climbStairs(self, n: int) -> int:
         for i in range(2,n+2):
             fib.append(fib[i-1]+fib[i-2])
         return fib[n+1]
+
+class Solution:
+    def climbStairs(self, n: int) -> int:
+        a,b=1,1
+        while n>0:
+            a,b = b,a+b
+            n-=1
+        return a