JavaPriorityQueue自定义权重任务实现方法

public class Task {
    private String name;
    private int priority;        // 数值越小优先级越高（默认逻辑）
    private long deadline;       // 时间戳，越早越紧急

    public Task(String name, int priority, long deadline) {
        this.name = name;
        this.priority = priority;
        this.deadline = deadline;
    }

    // getter 方法（必须有，Comparator 会用到）
    public int getPriority() { return priority; }
    public long getDeadline() { return deadline; }
    public String getName() { return name; }
}

// 按 priority 升序 + deadline 升序（双关键排序）
PriorityQueue taskQueue = new PriorityQueue<>((a, b) -> {
    int p = Integer.compare(a.getPriority(), b.getPriority());
    if (p != 0) return p;
    return Long.compare(a.getDeadline(), b.getDeadline());
});

public class DynamicTaskComparator implements Comparator {
    private SortStrategy strategy = SortStrategy.BY_PRIORITY;

    public void setStrategy(SortStrategy s) { this.strategy = s; }

    @Override
    public int compare(Task a, Task b) {
        return switch (strategy) {
            case BY_PRIORITY -> Integer.compare(a.getPriority(), b.getPriority());
            case BY_DEADLINE -> Long.compare(a.getDeadline(), b.getDeadline());
            case BY_COST -> Integer.compare(a.getCost(), b.getCost()); // 假设有 cost 字段
        };
    }
}

// 使用时：
DynamicTaskComparator comp = new DynamicTaskComparator();
PriorityQueue queue = new PriorityQueue<>(comp);
comp.setStrategy(SortStrategy.BY_DEADLINE); // 切换策略后，新插入元素生效
// 注意：已有元素不会自动重排，需重建队列或手动处理