Question

排序方法应返回一个字符串，该字符串以逗号分隔的整数列表，按升序排序。我的代码没有按4或更大的大小排序。如果没有system.out.println（），我也没有在控制台中获得返回类型的任何内容。任何建议/帮助表示赞赏。



import java.util.ArrayList;

public class Sorting {  
    public static void main(String[] args) 
    {
        ArrayList<Integer> alInput = makeArray(5);
        ArraySorter(alInput);

    }
    public static String ArraySorter (ArrayList<Integer> alSort) 
    {
        if (alSort.size()<=1)
        {
            return String.valueOf(alSort.get(0)) ;
        }
        int iMin = alSort.get(0);
        int iMinIndex = 0;
        for (int i = 0;i<alSort.size();i++ )
        {
            if (alSort.get(i)<iMin)
            {
                iMin = alSort.get(i);
                iMinIndex = i;
            }
        }
        alSort.remove(iMinIndex);
        System.out.println(String.valueOf(iMin) + ArraySorter (alSort));
        return String.valueOf(iMin) + ArraySorter (alSort);
    }

    public static ArrayList<Integer> makeArray(int iSize)
    {
        ArrayList<Integer> alNum = new ArrayList<Integer>();

        for (int i = 0; i<iSize;i++)
        {
            alNum.add((int )(Math.random() * 100 + 1));
        }
        System.out.println(alNum);
        return alNum;
    }
}

Answer 1

为什么不尝试这种简单方法，

alInput.sort(null);
        String myString = "";
        for (int i=0;i<alInput.size();i++){
            myString  = myString + String.valueOf(alInput.get(i)) + ",";
        }
        myString= myString.substring(0,myString.length()-1);
        System.out.println(myString);

Answer 2

尝试一下：我添加了一些评论，解释了我为fixe所做的更改。希望它有所帮助：）

import java.util.ArrayList;

public class Sorting {  
    public static void main(String[] args) 
    {
        ArrayList<Integer> alInput = makeArray(5);

        // now you can get the sorted string :)
        String sortedResult = ArraySorter(alInput);
        System.out.println("The sorted array is : " + sortedResult);

    }
    public static String ArraySorter (ArrayList<Integer> alSort) 
    {
        int iMin = alSort.get(0);
        int iMinIndex = 0;
        for (int i = 0;i<alSort.size();i++ )
        {
            if (alSort.get(i)<iMin)
            {
                iMin = alSort.get(i);
                iMinIndex = i;
            }
        }
        alSort.remove(iMinIndex);

        // added this one in myself, this is your base case for preventing a stack overflow:
        if (alSort.size() == 0) {
            return String.valueOf(iMin);
        }

        return String.valueOf(iMin) + "," + ArraySorter (alSort); // changed from : String.valueOf(iMin) + ArraySorter (alSort);
    }

    public static ArrayList<Integer> makeArray(int iSize)
    {
        ArrayList<Integer> alNum = new ArrayList<Integer>();

        for (int i = 0; i<iSize;i++)
        {
            alNum.add((int )(Math.random() * 100 + 1));
        }
        System.out.println(alNum);
        return alNum;
    }
}

使用ArrayList <integer>对整数进行排序

2 个答案: