各种排序算法java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[i]=data[i]; 
        } 
        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[i] = data[i]; 
        } 
        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[i]; 
            } 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[i]; 
                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; 
            } 
        }

    }

}

SortUtil:

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[i]; 
        data[i] = data[j]; 
        data[j] = temp; 
    } 
}

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