备战校招——常见排序

算法简单，但要想写出稳定健壮性好的排序程序还是很有挑战的，尤其是对边界的控制。

直接上干货吧，Resource Code.....:

public class Sort {

    public static void main(String [] argv){
        
        
        int [] source0 = {5,3,7,9,1,2,6,4,8};
        int [] source1 = {5,3,7,9,1,2,6,4,8};
        int [] source2 = {5,3,7,9,1,2,6,4,8};
        int [] source3 = {5,3,7,9,1,2,6,4,8};
        //*  快排测试   *//
        Sort test = new Sort();            
        test.Quick_sort(source0,0,source0.length-1);
        System.out.println("Quick sort result:");
        for (int k:source0){
            System.out.print(" "+k);
        }
        System.out.println();
        
        //*  冒泡测试   *//
        test.Bubble_sort(source1);
        System.out.println("Bubble sort result:");
        for (int k:source1){
            System.out.print(" "+k);
        }
        System.out.println();

        //*  归并测试   *//
        test.Merge_sort(source2, 0, source2.length-1);
        System.out.println("Merge sort result:");
        for (int k:source2){
            System.out.print(" "+k);
        }
        System.out.println();
        
        //*  堆排测试   *//
        test.Heap_sort(source3);
        System.out.println("Heap sort result:");
        for (int k:source3){
            System.out.print(" "+k);
        }
    }
    
    //*  堆排序   *//
    public void Heap_sort(int[] arr){
        int [] Result = new int[arr.length];

        for(int i=0; i<arr.length; i++){
            Heap_up(Result,i, arr[i]);
        }
        //System.out.println("............");
        for (int i=arr.length; i>=1; i--){
            //System.out.print(" "+Result[0]);
            Heap_down(Result,i);
        }    
        for(int i=0; i<arr.length; i++){
            arr[i]=Result[arr.length-1-i];
            //System.out.println(Result[i]);
        }
    }
    
    public void Heap_up(int[] arr,int n, int n_Num){
        
        arr[n]=n_Num;    
        Heap_up_adjust(arr,n);
        
    }
        
    public void Heap_up_adjust(int[] arr,int i){
        
        int j,temp;
        j=(i-1)/2;
        temp = arr[i];
        while(j>=0&&i!=0){
            
            if(arr[j]<=temp)
                break;
            arr[i]=arr[j];
            i=j;
            j=(i-1)/2;
        }
        arr[i]=temp;        
    }
    
    public void Heap_down(int[] arr,int n){
        
        int tmp = arr[0];
        arr[0]=arr[n-1];
        arr[n-1]=tmp;    
        Heap_down_adjust(arr, n);
    }
    
    public void Heap_down_adjust(int[] arr, int n){
        
        int i=0;
        int j = 2*i+1;
        int tmp=arr[0];
        while(j<n-1){
            if (j + 1 < n-1 && arr[j + 1] < arr[j]) 
                j++;
            if(arr[j]>=tmp)
                break;
            arr[i]=arr[j];            
            i=j;
            j=2*i+1;
        }
        arr[i]=tmp;
    }
    
    //*  归并排序 *//
    public void Merge_sort(int[] arr, int x, int y){
        int mid = (x+y+1)/2;
        //System.out.println(mid);
        if(mid-1>x) Merge_sort(arr,x,mid-1);
        if(y>mid) Merge_sort(arr,mid,y);        
        merge(arr,x,mid,y);    
    }
    public void merge(int[] arr, int s, int m, int t){
        int[] tmp = new int[t-s+1];
        int i = 0;
        int j = s;
        int k = m;
        while(!(j==m&&k==t+1)){
            while(j<m){
                if(k==t+1){
                    tmp[i]=arr[j];
                    //System.out.println(tmp[i]+" "+arr[j]);
                    //System.out.println("temp "+i+" "+tmp[i]+" "+j+" "+arr[j]);
                    i++;
                    j++;
                
                }
                else{
                    if(arr[j]<=arr[k]){
                    tmp[i]=arr[j];
                    //System.out.println(tmp[i]+" "+arr[j]);
                    //System.out.println("temp "+i+" "+tmp[i]+" "+j+" "+arr[j]);
                    i++;
                    j++;
                    }
                    else
                        break;
                }
                    
            }
            while(k<=t){
                if(j==m){
                    tmp[i]=arr[k];
                    //System.out.println(tmp[i]+" "+arr[k]);
                    //System.out.println("temp "+i+" "+tmp[i]+" "+k+" "+arr[k]);
                    i++;
                    k++;
                }
                else{
                    if(arr[k]<=arr[j]){
                    
                    tmp[i]=arr[k];
                    //System.out.println(tmp[i]+" "+arr[j]);
                    //System.out.println("temp "+i+" "+tmp[i]+" "+k+" "+arr[k]);
                    i++;
                    k++;
                    }
                    else
                        break;
                }
                    
            }
        }    
        for(int p=s; p<=t; p++){
            arr[p]=tmp[p-s];
            //System.out.print(" "+arr[p]);
        }
    }
    
    //* 冒泡排序 *//
    public void Bubble_sort(int[] arr){
        
        for(int i=0; i<arr.length-1;i++){
            for(int j=0; j<arr.length-1-i;j++){
                //System.out.println("i: "+i+"  j: "+j);
                if(arr[j]>arr[j+1]){
                    int temp =arr[j];
                    arr[j]=arr[j+1];
                    arr[j+1]=temp;
                }
            }
            
        }
        
    }
    
    //* 快速排序 *//
    public void Quick_sort(int[] arr, int low, int high)
    {
    int l=low;
    int h=high;
    int povit=arr[low];

     while(l<h)
     {
     while(l<h&&arr[h]>=povit)
     h--;
     if(l<h){
     int temp=arr[h];
     arr[h]=arr[l];
     arr[l]=temp;
     l++;
     }
     
     while(l<h&&arr[l]<=povit)
     l++;
     
     if(l<h){
     int temp=arr[h];
     arr[h]=arr[l];
     arr[l]=temp;
     h--;
     }
     }
    // System.out.print(arr);
    // System.out.print("l="+(l+1)+"h="+(h+1)+"povit="+povit+"
");
     if(l>low) Quick_sort(arr,low,l-1);
     if(h<high) Quick_sort(arr,l+1,high);
     }
        
    
}