Google translates this as:

Perhaps the task is not for my level, but I think that the condition of the task is crooked and the result that should be obtained does not at all coincide with the requirements of the task conditions

Let me suggest one approach. Go through the customers in order by arrival day. For each customer, go through the already allocated rooms. If that customer's arrival day is larger than the largest departure day of any customer who has been previously allocated that room, the customer can go into that room. If no such room exists, create a new room and put the customer there.

This is the basic idea. There are some details that you have to take care of to make it work.