各类排序算法java的实现

插入排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;
/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class InsertSort implements SortUtil.Sort{

  /* (non-Javadoc)
  * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
  */
  public void sort(int[] data) {
    int temp;
    for(int i=1;i<data.length;i++){
        for(int j=i;(j>0)&&(data[j]<data[j-1]);j--){
          SortUtil.swap(data,j,j-1);
        }
    }
  }
}

冒泡排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class BubbleSort implements SortUtil.Sort{

  /* (non-Javadoc)
  * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
  */
  public void sort(int[] data) {
    int temp;
    for(int i=0;i<data.length;i++){
        for(int j=data.length-1;j>i;j--){
          if(data[j]<data[j-1]){
            SortUtil.swap(data,j,j-1);
          }
        }
    }
  }
}

选择排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class SelectionSort implements SortUtil.Sort {

  /*
  * (non-Javadoc)
  *
  * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
  */
  public void sort(int[] data) {
    int temp;
    for (int i = 0; i < data.length; i++) {
        int lowIndex = i;
        for (int j = data.length - 1; j > i; j--) {
          if (data[j] < data[lowIndex]) {
            lowIndex = j;
          }
        }
        SortUtil.swap(data,i,lowIndex);
    }
  }
}

Shell排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class ShellSort implements SortUtil.Sort{

  /* (non-Javadoc)
  * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
  */
  public void sort(int[] data) {
    for(int i=data.length/2;i>2;i/=2){
        for(int j=0;j<i;j++){
          insertSort(data,j,i);
        }
    }
    insertSort(data,0,1);
  }

  /**
  * @param data
  * @param j
  * @param i
  */
  private void insertSort(int[] data, int start, int inc) {
    int temp;
    for(int i=start+inc;i<data.length;i+=inc){
        for(int j=i;(j>=inc)&&(data[j]<data[j-inc]);j-=inc){
          SortUtil.swap(data,j,j-inc);
        }
    }
  }
}

快速排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class QuickSort implements SortUtil.Sort{

  /* (non-Javadoc)
  * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
  */
  public void sort(int[] data) {
    quickSort(data,0,data.length-1);
  }
  private void quickSort(int[] data,int i,int j){
    int pivotIndex=(i+j)/2;
    //swap
    SortUtil.swap(data,pivotIndex,j);

    int k=partition(data,i-1,j,data[j]);
    SortUtil.swap(data,k,j);
    if((k-i)>1) quickSort(data,i,k-1);
    if((j-k)>1) quickSort(data,k+1,j);
  }

  /**
  * @param data
  * @param i
  * @param j
  * @return
  */
  private int partition(int[] data, int l, int r,int pivot) {
    do{
      while(data[++l]<pivot);
      while((r!=0)&&data[--r]>pivot);
      SortUtil.swap(data,l,r);
    }
    while(l<r);
    SortUtil.swap(data,l,r);
    return l;
  }
}

改进后的快速排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class ImprovedQuickSort implements SortUtil.Sort {

  private static int MAX_STACK_SIZE=4096;
  private static int THRESHOLD=10;
  /* (non-Javadoc)
  * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
  */
  public void sort(int[] data) {
    int[] stack=new int[MAX_STACK_SIZE];

    int top=-1;
    int pivot;
    int pivotIndex,l,r;

    stack[++top]=0;
    stack[++top]=data.length-1;

    while(top>0){
        int j=stack[top--];
        int i=stack[top--];

        pivotIndex=(i+j)/2;
        pivot=data[pivotIndex];

        SortUtil.swap(data,pivotIndex,j);

        //partition
        l=i-1;
        r=j;
        do{
          while(data[++l]<pivot);
          while((r!=0)&&(data[--r]>pivot));
          SortUtil.swap(data,l,r);
        }
        while(l<r);
        SortUtil.swap(data,l,r);
        SortUtil.swap(data,l,j);

        if((l-i)>THRESHOLD){
          stack[++top]=i;
          stack[++top]=l-1;
        }
        if((j-l)>THRESHOLD){
          stack[++top]=l+1;
          stack[++top]=j;
        }

    }
    //new InsertSort().sort(data);
    insertSort(data);
  }
  /**
  * @param data
  */
  private void insertSort(int[] data) {
    int temp;
    for(int i=1;i<data.length;i++){
        for(int j=i;(j>0)&&(data[j]<data[j-1]);j--){
          SortUtil.swap(data,j,j-1);
        }
    }
  }
}

归并排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class MergeSort implements SortUtil.Sort{

  /* (non-Javadoc)
  * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
  */
  public void sort(int[] data) {
    int[] temp=new int[data.length];
    mergeSort(data,temp,0,data.length-1);
  }

  private void mergeSort(int[] data,int[] temp,int l,int r){
    int mid=(l+r)/2;
    if(l==r) return ;
    mergeSort(data,temp,l,mid);
    mergeSort(data,temp,mid+1,r);
    for(int i=l;i<=r;i++){
        temp=data;
    }
    int i1=l;
    int i2=mid+1;
    for(int cur=l;cur<=r;cur++){
        if(i1==mid+1)
          data[cur]=temp[i2++];
        else if(i2>r)
          data[cur]=temp[i1++];
        else if(temp[i1]<temp[i2])
          data[cur]=temp[i1++];
        else
          data[cur]=temp[i2++];
    }
  }
}

改进后的归并排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class ImprovedMergeSort implements SortUtil.Sort {

  private static final int THRESHOLD = 10;

  /*
  * (non-Javadoc)
  *
  * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
  */
  public void sort(int[] data) {
    int[] temp=new int[data.length];
    mergeSort(data,temp,0,data.length-1);
  }

  private void mergeSort(int[] data, int[] temp, int l, int r) {
    int i, j, k;
    int mid = (l + r) / 2;
    if (l == r)
        return;
    if ((mid - l) >= THRESHOLD)
        mergeSort(data, temp, l, mid);
    else
        insertSort(data, l, mid - l + 1);
    if ((r - mid) > THRESHOLD)
        mergeSort(data, temp, mid + 1, r);
    else
        insertSort(data, mid + 1, r - mid);

    for (i = l; i <= mid; i++) {
        temp = data;
    }
    for (j = 1; j <= r - mid; j++) {
        temp[r - j + 1] = data[j + mid];
    }
    int a = temp[l];
    int b = temp[r];
    for (i = l, j = r, k = l; k <= r; k++) {
        if (a < b) {
          data[k] = temp[i++];
          a = temp;
        } else {
          data[k] = temp[j--];
          b = temp[j];
        }
    }
  }

  /**
  * @param data
  * @param l
  * @param i
  */
  private void insertSort(int[] data, int start, int len) {
    for(int i=start+1;i<start+len;i++){
        for(int j=i;(j>start) && data[j]<data[j-1];j--){
          SortUtil.swap(data,j,j-1);
        }
    }
  }
}

堆排序:

package org.rut.util.algorithm.support;

import org.rut.util.algorithm.SortUtil;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class HeapSort implements SortUtil.Sort{

  /* (non-Javadoc)
  * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
  */
  public void sort(int[] data) {
    MaxHeap h=new MaxHeap();
    h.init(data);
    for(int i=0;i<data.length;i++)
        h.remove();
    System.arraycopy(h.queue,1,data,0,data.length);
  }

  private static class MaxHeap{


    void init(int[] data){
        this.queue=new int[data.length+1];
        for(int i=0;i<data.length;i++){
          queue[++size]=data;
          fixUp(size);
        }
    }

    private int size=0;

    private int[] queue;

    public int get() {
        return queue[1];
    }

    public void remove() {
        SortUtil.swap(queue,1,size--);
        fixDown(1);
    }
    //fixdown
    private void fixDown(int k) {
        int j;
        while ((j = k << 1) <= size) {
          if (j < size && queue[j]<queue[j+1])
            j++;
          if (queue[k]>queue[j]) //不用交换
            break;
          SortUtil.swap(queue,j,k);
          k = j;
        }
    }
    private void fixUp(int k) {
        while (k > 1) {
          int j = k >> 1;
          if (queue[j]>queue[k])
            break;
          SortUtil.swap(queue,j,k);
          k = j;
        }
    }
  }
}

主程序:

package org.rut.util.algorithm;

import org.rut.util.algorithm.support.BubbleSort;
import org.rut.util.algorithm.support.HeapSort;
import org.rut.util.algorithm.support.ImprovedMergeSort;
import org.rut.util.algorithm.support.ImprovedQuickSort;
import org.rut.util.algorithm.support.InsertSort;
import org.rut.util.algorithm.support.MergeSort;
import org.rut.util.algorithm.support.QuickSort;
import org.rut.util.algorithm.support.SelectionSort;
import org.rut.util.algorithm.support.ShellSort;

/**
* @author treeroot
* @since 2006-2-2
* @version 1.0
*/
public class SortUtil {
  public final static int INSERT = 1;

  public final static int BUBBLE = 2;

  public final static int SELECTION = 3;

  public final static int SHELL = 4;

  public final static int QUICK = 5;

  public final static int IMPROVED_QUICK = 6;

  public final static int MERGE = 7;

  public final static int IMPROVED_MERGE = 8;

  public final static int HEAP = 9;

  public static void sort(int[] data) {
    sort(data, IMPROVED_QUICK);
  }
  private static String[] name={
        "insert","bubble","selection","shell","quick","improved_quick","merge","improved_merge","heap"
  };

  private static Sort[] impl=new Sort[]{
        new InsertSort(),
        new BubbleSort(),
        new SelectionSort(),
        new ShellSort(),
        new QuickSort(),
        new ImprovedQuickSort(),
        new MergeSort(),
        new ImprovedMergeSort(),
        new HeapSort()
  };

  public static String toString(int algorithm){
    return name[algorithm-1];
  }

  public static void sort(int[] data, int algorithm) {
    impl[algorithm-1].sort(data);
  }

  public static interface Sort {
    public void sort(int[] data);
  }

  public static void swap(int[] data, int i, int j) {
    int temp = data;
    data = data[j];
    data[j] = temp;
  }
}

Posted on 2006-12-23 05:41 Clark Zheng 阅读(442) 评论(0) 编辑收藏举报

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