Create 0069-sqrtx.py

Author: TheHong

Diff for: python/0069-sqrtx.py

@@ -0,0 +1,12 @@
+class Solution:
+    def mySqrt(self, x: int) -> int:
+        l, r = 0, x
+        while l <= r:
+            mid = (l + r) // 2
+            if mid * mid == x:
+                return mid
+            if mid * mid < x:
+                l = mid + 1
+            else:
+                r = mid - 1
+        return r