Add Subscripts to Duplicate Packages and Output YAML Dependencies

optiver Given a list of packages [A,B,C,A,C,A], you need to save all dependencies in a YAML format. When there are duplicate packages, add a subscript to the string, for example, generate a new list [A,B,C,A1,C1,A2]. Write a Python program to achieve this. Example Input A B C A C A