Bubblesort数组升序

Question

我有一个数据文件,我需要通过Make && Model of vehicle对信息进行排序.我的bubbleort不起作用,你能帮我解决我的问题吗？非常感谢你!PS我不能有额外的方法:(如果我删除getMake()方法,它的工作原理,但&& getModel根本不起作用:(

    public static void sortByVehicleMakeModel(Vehicle[] vehicles) {
        for(int y = 0; y < vehicles.length; y++) {
            for (int x = 0 ; x < vehicles.length - 1 ; x++){
                if((vehicles[x].getMake().compareToIgnoreCase(vehicles[x+1].getMake()) > 0) && (vehicles[x].getModel().compareToIgnoreCase(vehicles[x+1].getModel()) > 0)) {    
                    swap(vehicles, x, x + 1);
                }           
            }
        }
        for(int x = 0; x < vehicles.length - 1; x++){
            System.out.println(vehicles[x].getMake());
        }
    }

Answer 1

请按照以下步骤比较两辆车:

• 比较化妆两路车
• 如果它们不相等,则返回比较结果
• 如果他们是平等的,比较模型,并返回结果

您应该使用使用上述逻辑比较两个Vehicle的方法替换if语句中的代码.

像这样的东西:

if (compareVehicles(vehicles[x], vehicles[x + 1]) > 0) {
    swap(vehicles, x, x + 1);
}

要以正确的方式执行此操作,您应该使Vehicle实现可比较.

这样你就可以将上面的逻辑放在compareTo方法中.

这将允许您简单地执行此操作:

if (vehicles[x].compareTo(vehicles[x + 1]) > 0) {
    swap(vehicles, x, x + 1);
}

这是一个如何实现Comparable的简单示例:

class Vehicle implements Comparable<Vehicle> {
    private String make;
    private String model;

    public int compareTo(Vehicle other) {
        if (other == null) {
            return -1;
        }
        int compareVal = make.compareToIgnoreCase(other.make);
        if (compareVal == 0) {
            return model.compareToIgnoreCase(other.model);
        }
        else {
            return compareVal;
        }
    }

}

好的...因为已经有几天了,我只会告诉你如何做到这一点.

public static void sortVehicles(Vehicle[] vehicles) {
    for (int i = 0; i < vehicles.length - 1; i++) {
        Vehicle curr = vehicles[i];
        Vehicle next = vehicles[i + 1];
        String currMake = curr.getMake();
        String nextMake = next.getMake();
        int compareVal = currMake.compareToIgnoreCase(nextMake);
        // if the makes are the same, we need to compare the models
        if (compareVal == 0) {
            String currModel = curr.getModel();
            String nextModel = next.getModel();
            compareVal = currModel.compareToIgnoreCase(nextModel);
        }
        if (compareVal > 0) {
            swap(vehicles, i, i + 1);
        }
    }

    for (Vehicle v : vehicles) {
        System.out.println(v.getMake());
    }
}