Added twice-counter

Author: avidLearnerInProgress

amazon/twice_counter.py

@@ -0,0 +1,15 @@
+#code
+from collections import Counter
+n = int(input())
+
+for i in range(n):
+    _ = int(input())
+    tc = list(map(str, input().split(' ')))
+    counter = Counter()
+    for i in range(len(tc)):
+        counter[tc[i]] += 1
+    cn = 0
+    for k,v in counter.items():
+        if v == 2:
+            cn += 1
+    print(cn)