There is a new office building with a total of 21 floors and four elevators. The basic parameters of all elevators are shown in the table below, and their use regulations are as follows:
Floor numbers are 0~20, of which No. 0 is the basement
floor. Elevators with floor restrictions do not stop at the corresponding floors, such as single and double floors.
All elevators are controlled by a unified button
. Please design and implement an elevator control program according to the above requirements. If there is a graphic display better