program to display the duplicate values in an array

Write a program to display the duplicate values in an array.
Formulas Needed: None
Final submission along with Code
Opening Documentation: the header block should include the following:
•Program name/syntax
•Description of what the program does
•Summary of the problem's specifications and assumptions
•License info (optional)
•References to sources of additional information used
•Parameters
•Class/Program Invariant (ensure these conditions are true)
•Algorithm(s) used (including any special notes)
•Output (any print statements, files created, etc.)
•Return values (does it return any parameters?)
•Name of the authors (plus contact info)
•Creation & modification dates