upload new problem with solution

Microsoft_Problems/Microsoft_Problem_10.py

@@ -0,0 +1,30 @@
+"""
+This problem was asked by Microsoft.
+
+Implement the singleton pattern with a twist. First, instead of storing one instance, store two instances. And in every even call of getInstance(), return the first instance and in every odd call of getInstance(), return the second instance.
+"""
+call_times = 0
+
+
+class String:
+    def __init__(self):
+        self.string = None
+
+    def get_instance(self):
+        global call_times
+        call_times += 1
+        first_instance = String()
+        first_instance.string = "instance 1"
+        second_instance = String()
+        second_instance.string = "instance 2"
+        if call_times % 2 == 0:
+            return first_instance
+        else:
+            return second_instance
+
+
+# Driver code
+for i in range(6):
+    obj = String().get_instance()
+    print("".join("Call n°" + str(i)) + ":")
+    print(obj.string)