常见排序代码集合-java

import java.io.*;
import java.util.*;
import java.lang.*;

public class pGeneralSorting{

    public static void BubbleSort(Comparable[] a){
        boolean switched = true;
        for(int i=0;i<a.length-1 && switched;i++){
            switched = false;
            for(int j=0;j<a.length-i-1;j++)
                if(a[j].compareTo(a[j+1]) > 0){
                    switched = true;
                    Comparable hold = a[j];
                    a[j] = a[j+1];
                    a[j+1] = hold;
                }
        }
    }

    public static void SelectionSort(Comparable[] a){
        for(int i = a.length-1;i>0;i--){
            Comparable large = a[0];
            int indx = 0;
            for(int j = 1;j <= i;j++)
                if(a[j].compareTo(large) > 0){
                    large = a[j];
                    indx = j;
                }
            a[indx] = a[i];
            a[i] = large;
        }
    }

    public static void InsertionSort(Comparable[] a){
        int i,j;
        Comparable e;
        for(i=1;i<a.length;i++){
            e = a[i];
            for(j=i-1;j>=0 && a[j].compareTo(e) > 0;j--)
                a[j+1] = a[j];
            a[j+1] = e;
        }
    }

    public static void HeapSort(Comparable[] a){
        int i,f,s;
        for(i=1;i<a.length;i++){
            Comparable e = a[i];
            s = i;
            f = (s-1)/2;
            while(s > 0 && a[f].compareTo(e) < 0){
                a[s] = a[f];
                s = f;
                f = (s-1)/2;
            }
            a[s] = e;
        }
        for(i=a.length-1;i>0;i--){
            Comparable value = a[i];
            a[i] = a[0];
            f = 0;
            if(i == 1)
                s = -1;
            else
                s = 1;
            if(i > 2 && a[2].compareTo(a[1]) > 0)
                s = 2;
            while(s >= 0 && value.compareTo(a[s]) < 0){
                a[f] = a[s];
                f = s;
                s = 2*f+1;
                if(s+1 <= i-1 && a[s].compareTo(a[s+1]) < 0)
                    s = s+1;
                if(s > i-1)
                    s = -1;
            }
            a[f] = value;
        }
    }

    public static void MergeSort(Comparable[] a){
        Comparable[] aux = new Comparable[a.length];
        int i,j,k,l1,l2,size,u1,u2;
        size = 1;
        while(size < a.length){
            l1 = k = 0;
            while((l1 + size) < a.length){
                l2 = l1 + size;
                u1 = l2 - 1;
                u2 = (l2+size-1 < a.length) ?
                    l2 + size-1:a.length-1;
                for(i=l1,j=l2;i <= u1 && j <= u2;k++)
                    if(a[i].compareTo(a[j]) <= 0)
                        aux[k] = a[i++];
                    else
                        aux[k] = a[j++];
                for(;i <= u1;k++)
                    aux[k] = a[i++];
                for(;j <= u2;k++)
                    aux[k] = a[j++];
                l1 = u2 + 1;
            }
            for(i=l1;k < a.length;i++)
                aux[k++] = a[i];
            for(i=0;i < a.length;i++)
                a[i] = aux[i];
            size *= 2;
        }
    }

    public static void main(String[] args){
        Integer[] a = new Integer[10];
        System.out.print("starting.../nadding:");
        for(int i=0;i<a.length;i++){
            a[i] = new Integer((int)(Math.random()*100));
            System.out.print(" " + a[i]);
        }
        BubbleSort(a);
        System.out.print("/nprinting:");
        for(int i=0;i<a.length;i++){
            System.out.print(" " + a[i]);
        }
        System.out.println("/nDone ;-)");
    }
}