My basic solution for elevatorsaga.com

elevatorsaga.js

{
    init: function(elevators, floors) {
        const lessMoves = false;
        var upQueue = [];
        var downQueue = [];

        moveToFloorNum = (elevator, floorNum, force=false) => {
            if (elevator.destinationQueue.includes(floorNum)) {
                elevator.goToFloor(floorNum, force);

                return;
            }

            let duplicate = false;
            _.each(elevators, e => {
                if (e.destinationQueue.includes(floorNum)) {
                    duplicate = true;
                }
            });

            if (duplicate) {
                return;
            }

            elevator.goToFloor(floorNum, force);
        };

        removeFloorFromAllQueues = floorNum => {
            var uppressedIndex = upQueue.indexOf(floorNum);

            if (uppressedIndex > -1) {
                upQueue.splice(uppressedIndex, 1);
            }

            var downPressedIndex = downQueue.indexOf(floorNum);

            if(downPressedIndex > -1){
                downQueue.splice(downPressedIndex, 1);
            }
        };

        _.each(elevators, elevator => {
            elevator.on("floor_button_pressed", function(floorNum) {
                elevator.goToFloor(floorNum);
            });

            elevator.on("idle", () => {
                var floorNum;

                if (downQueue.length > 0) {
                    floorNum = downQueue.pop();
                } else if (upQueue.length > 0){
                    floorNum = upQueue.pop();
                } else {
                    floorNum = elevator.currentFloor();
                }

                if (lessMoves) {
                    moveToFloorNum(elevator, floorNum);
                } else {
                    elevator.goToFloor(floorNum);
                }
            });

            elevator.on("stopped_at_floor", () => {
                var floorNum = elevator.currentFloor();
                var uppressedIndex = upQueue.indexOf(floorNum);
                var downPressedIndex = downQueue.indexOf(floorNum);

                removeFloorFromAllQueues(floorNum);
            });

            elevator.on("passing_floor", (floorNum, direction) => {
                var uppressedIndex = upQueue.indexOf(floorNum);
                var downPressedIndex = downQueue.indexOf(floorNum);

                if (!elevator.destinationQueue.includes(floorNum)) {
                    if (elevator.loadFactor() > 0.95) {
                        return;
                    }

                    if ((uppressedIndex+downPressedIndex) == -2) {
                        return;
                    }
                }

                removeFloorFromAllQueues(floorNum);

                if (lessMoves) {
                    moveToFloorNum(elevator, floorNum);
                } else {
                    elevator.goToFloor(floorNum);
                }
            });
        });

        _.each(floors, function(floor) {
            floor.on("up_button_pressed", () => {
                upQueue.push(floor.level);
            });
            floor.on("down_button_pressed", () => {
                downQueue.push(floor.level);
            });
        });
    },
        update: function(dt, elevators, floors) {
            _.each(elevators, e => {
                e.destinationQueue = Array.from(new Set(e.destinationQueue));
                e.checkDestinationQueue();
            });
        }
}