missing number problem

algorithms/Python/arrays/missing_number.py

@@ -0,0 +1,15 @@
+"""
+Algorithm Type: Array Traversal
+Time Complexity: O(n)
+"""
+numbers = [1, 2, 4, 3, 6, 7, 9, 8, 10]
+n = 10
+
+def missing_number(numbers, n):
+    s = sum(numbers)
+    expected_s = (n*(n+1))//2 #for C++ or similar, keep in mind expected_s can overflow MAX INT limit.
+    return expected_s - s
+
+
+if __name__ == "__main__":
+  print(missing_number(numbers, n))