12.3.    441

     ,    
 Bus Company.         -
  ,        -
       .  -
:       ?    -
   .

struct existing_trip{
//. . .
string From;

time Departures-
string To;

time Arrival;

//. . .

};

       -
      .

set<existing_trips> BusTripKnowl edge ;

            
BusTripKnowledge,      ,      -
          .
,          .

//. . .

existing_trip Trip;

Trip.From.append("Toledo") ;

Trip.To.append("Cleveland") ;

Trip.Departure("4:30") ;

Trip.Arrival("5:45");

BusTripKnowledge.insert(Trip) ;

//. . .

       BusTripKnowledge,  -
        Bus Company  -
 .    ,     
 -  .      -   
 ,    :

   ;

   ;

   ;

  -.

,       Bus Company   -
  (     ),       -
  .    :    -
   ?         
      ,   -
    -.     . -
   BusTripKnowledge      -
     .     .   
   "-",     ,  