Probleum Statement:
Consider we are building an algorithm for an elevator system for a highrise building like Burj Khalifa. Typically these buildings would have a considerable number of floors / stops. E.g. Burj Khalifa has 165 but let us assume that the number can go upto 200. Given the number of lifts are N, M people who are requesting lifts rapidly. Design an algorithm which would solve these problems
Minimise the wait time for each lift. In the mornings a lot of people would be going to their respective offices [8-9] so in the morning load of people going up would be high In the evenings a lot of people would be going down so the load will be high but it will be random Sometimes when a lift arrives it is full. We would like to avoid that situation also.
Solution:
Whenever a passenger presses an elevator button it becomes a request and it is added to requests array. Requests Array contains list of request objects.
Request : { id floorNumber direction - (up or down) time assigned : elevatorNumber } There is list of elevators. An Elevator object has following schema.
Elevator { elevatorNumber state : idle/ up/ down fullCapacity : true / false floorNumber stops : [ ] (floor numbers in sorted order) }
Initialize all elevators as below
{ elevatorNumber = 1, 2, etc. (unique identifier) state = idle fullCapacity = false floorNumber = 0, 1, etc. stops [ ] - empty array }
When a request comes, check for the nearest elevator and assign the request to the elevator. The nearest elevator is chosen by checking elevators
- without full capacity
- finding the difference of floors with current passenger floor
- if an elevator is idle or the elevator going in the same direction as the passenger.
- reassign an already assigned elevator if elevator is fully loaded. Probleum Statement:
Consider we are building an algorithm for an elevator system for a highrise building like Burj Khalifa. Typically these buildings would have a considerable number of floors / stops. E.g. Burj Khalifa has 165 but let us assume that the number can go upto 200. Given the number of lifts are N, M people who are requesting lifts rapidly. Design an algorithm which would solve these problems
Minimise the wait time for each lift. In the mornings a lot of people would be going to their respective offices [8-9] so in the morning load of people going up would be high In the evenings a lot of people would be going down so the load will be high but it will be random Sometimes when a lift arrives it is full. We would like to avoid that situation also.
Solution:
Whenever a passenger presses an elevator button it becomes a request and it is added to requests array. Requests Array contains list of request objects.
Request : { id floorNumber direction - (up or down) time assigned : elevatorNumber } There is list of elevators. An Elevator object has following schema.
Elevator { elevatorNumber state : idle/ up/ down fullCapacity : true / false floorNumber stops : [ ] (floor numbers in sorted order) }
Initialize all elevators as below
{ elevatorNumber = 1, 2, etc. (unique identifier) state = idle fullCapacity = false floorNumber = 0, 1, etc. stops [ ] - empty array }
When a request comes, check for the nearest elevator and assign the request to the elevator. The nearest elevator is chosen by checking elevators
- without full capacity
- finding the difference of floors with current passenger floor
- if an elevator is idle or the elevator going in the same direction as the passenger.
- reassign an already assigned elevator if elevator is fully loaded.