import collections


def duplicates(replist):
    """
    Give dictionary of repeated elements (keys) and their indexes (array in values)

    :param replist: list to look for repetitions
    """
    counter=collections.Counter(replist)
    dups=[i for i in counter if counter[i]!=1]
    result={}
    for item in dups:
        result[item]=[i for i,j in enumerate(replist) if j==item]
    return result