public static void createContact(List<Account> accList){

    list<Contact> listContact = new list<Contact>();
    map<id,decimal> mapAcc = new map<id,decimal>();

    for(Account acc : accList){
        mapAcc.put(acc.id,acc.Number_Of_Location__c);
        system.debug('*********mapvalue'+mapAcc);
    }
    if(mapAcc.size()>0 && mapAcc!=null){
        for(id accId:mapAcc.keyset()){
            for(integer i=0;i<mapAcc.get(accId);i++){

                Contact con = new Contact();
                con.id=accId;
                con.LastName='contact'+i;
                listContact.add(con);
            }
        }
    }
  if(listContact.size()>0 && listContact!=null){
  insert listContact;
}
}