function solution(bridge_length, weight, truck_weights) {
    var totalTrucks = truck_weights.length;
    var answer = 0;
    var timeOnRoadPerTruck = [];
    var arrivedTruck = [];
    var onBridgeTruck = [];
    var onBridgeTruckWeights = 0;
    
    // 다리 위에 있는 트럭 무게의 합
    function sumTruckWeights () {
        let sum = 0;
        for (let w of onBridgeTruck) sum += w;
        return sum;
    }    
    
    // 다리 위에서 트럭의 이동거리
    function goesbyTime () {
        for (let i = 0; i < timeOnRoadPerTruck.length; i++) {
            ++timeOnRoadPerTruck[i];
        }
    }

    // 다리 위에 있는 트럭 무게 다시 계산
    function initTruckWeights () {
        onBridgeTruckWeights = sumTruckWeights();
    } 
    
    while (arrivedTruck.length !== totalTrucks) {
        ++answer;        
        if (timeOnRoadPerTruck.length !== 0) goesbyTime();
        
        // 다리를 건넜는지 먼저 확인하여 처리
        if (timeOnRoadPerTruck[0] === bridge_length) {
            var truckOut = onBridgeTruck.shift();
            arrivedTruck.push(truckOut);
            timeOnRoadPerTruck.shift();
            initTruckWeights();
        }

        // 다리를 건널 트럭 추가
        if ((onBridgeTruckWeights + truck_weights[0]) <= weight) {
            var truckIn = truck_weights.shift();
            onBridgeTruck.push(truckIn);
            timeOnRoadPerTruck.push(0);
            initTruckWeights();
        }
    }
    return answer;
}