import java.util.*;

public class BankQueue {

    static class Customer {
        int arrivalTime;
        int processTime;

        public Customer(int arrivalTime, int processTime) {
            this.arrivalTime = arrivalTime;
            this.processTime = processTime;
        }
    }

    public static double calculateAverageWaitTime(List<Customer> customers, int maxProc, int maxWindow) {
        Queue<Integer>[] windows = new LinkedList[maxWindow];
        for (int i = 0; i < maxWindow; i++) {
            windows[i] = new LinkedList<>();
        }

        int totalWaitTime = 0;
        int numCustomersServed = 0;

        for (Customer customer : customers) {
            // 寻找最早空闲的窗口
            int minFinishTime = Integer.MAX_VALUE;
            int chosenWindow = -1;

            for (int i = 0; i < maxWindow; i++) {
                if (windows[i].isEmpty()) {
                    chosenWindow = i;
                    break;
                }
                int finishTime = windows[i].peek();
                if (finishTime < minFinishTime) {
                    minFinishTime = finishTime;
                    chosenWindow = i;
                }
            }

            // 计算等待时间
            int waitTime = Math.max(0, minFinishTime - customer.arrivalTime);
            totalWaitTime += waitTime;

            // 更新服务结束时间
            int serviceEndTime = customer.arrivalTime + waitTime + customer.processTime;
            if (serviceEndTime - customer.arrivalTime <= maxProc) {
                windows[chosenWindow].offer(serviceEndTime);
                numCustomersServed++;
            }
        }

        if (numCustomersServed == 0) {
            return 0; // 没有顾客被服务
        }

        return (double) totalWaitTime / numCustomersServed;
    }

    public static void main(String[] args) {
        // 假设的输入数据
        List<Customer> customers = Arrays.asList(
                new Customer(0, 3),
                new Customer(2, 3),
                new Customer(5, 4),
                new Customer(6, 2)
        );

        int maxProc = 10;
        int maxWindow = 2;

        double avgWaitTime = calculateAverageWaitTime(customers, maxProc, maxWindow);
        System.out.println("平均等待时间: " + avgWaitTime);
    }
}