367

Author: nlfox

367_Valid_Perfect_Square.py

@@ -0,0 +1,17 @@
+class Solution(object):
+    def isPerfectSquare(self, num):
+        """
+        :type num: int
+        :rtype: bool
+        """
+        left, right = 1, num
+        while left <= right:
+            mid = (left + right) / 2
+            r = mid * mid
+            if r < num:
+                left = mid + 1
+            elif r > num:
+                right = mid - 1
+            else:
+                return True
+        return False