使用节点而不是整数在Java中实现基数排序

Posted 2023-02-22

【中文标题】使用节点而不是整数在Java中实现基数排序

【英文标题】：Implementation of Radix sort in Java using Nodes instead of integers

【发布时间】：2015-12-21 12:26:52

【问题描述】：

我的数据结构类有一个最终项目，但我不知道该怎么做。我需要实现基数排序，并且我在很大程度上理解了这个概念。但是到目前为止，我在网上找到的所有实现都严格使用整数，我需要将它与我创建的另一个类型称为 Note 一起使用，它是一个带有 ID 参数的字符串。 这是我目前所拥有的，但不幸的是它没有通过任何 JUnit 测试。

package edu.drew.note;
public class RadixSort implements SortInterface 

     public static void Radix(Note[] note)

            // Largest place for a 32-bit int is the 1 billion's place
            for(int place=1; place <= 1000000000; place *= 10)
                // Use counting sort at each digit's place
                note = countingSort(note, place);
            

            //return note;
        

        private static Note[] countingSort(Note[] note, long place) //Where the sorting actually happens
            Note[] output = new Note[note.length]; //Creating a new note that would be our output.

            int[] count = new int[10];  //Creating a counter

            for(int i=0; i < note.length; i++) //For loop that calculates 
                int digit = getDigit(note[i].getID(), place);
                count[digit] += 1;
            

            for(int i=1; i < count.length; i++)
                count[i] += count[i-1];
            

            for(int i = note.length-1; i >= 0; i--)
                int digit = getDigit((note[i].getID()), place);

                output[count[digit]-1] = note[i];
                count[digit]--;
            

            return output;

        

        private static int getDigit(long value, long digitPlace)  //Takes value of Note[i] and i. Returns digit.
            return (int) ((value/digitPlace ) % 10);
        


        public Note[] sort(Note[] s)   //
             Radix(s);
             return s;
        


        //Main Method
        public static void main(String[] args) 
            // make an array of notes
            Note q = new Note(" ", " ");
            Note n = new Note("CSCI 230 Project Plan", 
                    "Each person will number their top 5 choices.\n" +
                    "By next week, Dr. Hill will assign which piece\n" +
                    "everyone will work on.\n");
            n.tag("CSCI 230");
            n.tag("final project");

            Note[] Note = q,n;
            //print out not id's
            System.out.println(Note + " Worked");
            //call radix
            Radix(Note);
            System.out.println(Note);
            //print out note_id's
        

    

【参考方案1】：

代替

public Note[] sort(Note[] s)   //
         Radix(s);
         return s;
    

我应该用过

public Note[] sort(Note[] s)   //
        s = Radix(s);
         return s;
    

并将Radix的变量类型从void更改为Note[].