在循环数组队列中查找最小值

Question

public class CanadaTour {
    
    
    private CircularArrayQueue<City> cityQueue;
    private Map map;
    private City startCity;
    
    
    public CanadaTour (String fileName) {
        map = new Map();
        cityQueue = new CircularArrayQueue<City>();
        loadData(fileName);
    }
    
    private void loadData (String file) {
        
        
        MyFileReader reader = new MyFileReader(file);
        
        reader.readString(); // First line of headers.
        
        String cityName = null;
        int locX = 0;
        int locY = 0;
        double earnings = 0;
        int cityID = 0;
        
        while (!reader.endOfFile()) {
            cityName = reader.readString();
            locX = reader.readInt();
            locY = reader.readInt();
            earnings = reader.readDouble();
            cityID ++;
            
            City city = new City(cityID, cityName, locX, locY, earnings);
            
            if (cityID == 1) {
                startCity = city;
            
            }
            cityQueue.enqueue(city);
            map.addCity(city);
        }
        
    }
    public City findNextCity (City currCity, double currMoney) {
        
        double distance = 0;
        
        City result = cityQueue.dequeue();
        if (result != currCity || result.isMarkedInStack() 
                || result.isMarkedOutOfStack())  //add other conditionals
            
            distance = distBetweenCities(result, currCity);
            cityQueue.enqueue(result);
            
        double distance1;   
        for (int i = 1; i < cityQueue.getLength(); i ++) {
            City result1 = cityQueue.dequeue();
            if (result1 != currCity || result1.isMarkedInStack() 
                    || result1.isMarkedOutOfStack()) { //add other conditionals
                
                distance1 = distBetweenCities(result1, currCity);
                if (distance1 < distance) {
                    distance = distance1;
                    return result1;
                }
                cityQueue.enqueue(result1);
                                
            }
        }
        return result;      
    }
    
    public double distBetweenCities (City city1, City city2) {
        
        double result =  Math.sqrt(Math.pow(city2.getX() - city1.getX(), 2) + 
                Math.pow(city2.getY() - city2.getY(), 2) * 1.0);
        return result;
        
    }
    
    public double calcFlightCost (double distance) {
        
        double flightCost;
        if (distance < 100.0) {
            flightCost = 127.00;
        } else {
            flightCost = (1.25 * distance) + 32.0;
        }
        
        return flightCost;
        
    }

到目前为止，这就是我的答案，但从逻辑上讲，我的答案对于findNextCity方法似乎是错误的。此外，我甚至不知道如何处理问题的第二部分（以下）。

我应该遍历cityQueue中的每个元素，使用下一种方法计算的欧几里德距离（distbetweencies），确定哪个元素最接近当前城市（从第一个参数）。我必须忽略已经标记在堆栈中或堆栈中的城市以及当前城市本身（否则，城市将始终是离自身最近的城市！）。如果找到的城市（与当前城市的距离最小）为null，则返回null。计算到这座城市的飞行费用，并确定用乐队目前的资金是否能负担得起。如果是，请返回城市，但如果负担不起，请返回null。

Answer 1

在不提供完整解决方案的情况下，您可能需要考虑以下几点：

• 您似乎正在出队和入队以查看队列的头部。如果您的CircularArrayQueue实现了Queue，它应该有一个peek方法，可以查看头部而不删除它。
• 过滤器条件中的或运算符可能应该是和（

您可能需要以下内容：

City closestCity = null;
for (City testCity: cityQueue) {
    if (testCity != currCity 
            && !testCity.isMarkedInStack() && !testCity.isMarkedOutOfStack()
            && (closestCity == null || distance(currCity, closestCity) > distance(currCity, testCity))
        closestCity == testCity;
}