几个排序算法

 

1.快速排序

 1 public class quicksorts {
 2     public static List<Integer> quicks(List<Integer> nums)
 3     {
 4         if(nums.size()<2)
 5             return nums;
 6         final List<Integer> lower=new ArrayList<Integer>();
 7         final List<Integer> higher=new ArrayList<Integer>();
 8         final int pivot=nums.get(0);
 9         for(int i=1;i<nums.size();i++)
10         {
11             if(nums.get(i)>pivot)
12                 higher.add(nums.get(i));
13             else lower.add(nums.get(i));
14         }
15         final List<Integer> con=quicks(lower);
16         con.add(pivot);
17         con.addAll(quicks(higher));
18         return con;
19     }
20 }

2.插入排序

 1 public class insertsorts {
 2     public static List<Integer> ins(final List<Integer> nums)
 3     {
 4         List<Integer> insertsorted=new LinkedList<>();
 5         ori:for(int num:nums)
 6         {
 7             for(int  i=0;i<insertsorted.size();i++)
 8             {
 9                 if(num<insertsorted.get(i))
10                     {insertsorted.add(i,num);
11                 continue ori;}
12             }
13             insertsorted.add(insertsorted.size(),num);    
14         }
15         return insertsorted; 
16     }
17 }

3.冒泡排序

 1 public  class bubblesort {
 2     public static void bubblesorts(int[] nums)
 3     {
 4         boolean flag;
 5         do
 6         {
 7             flag=false;
 8             for(int i=0;i<nums.length-1;i++)
 9             {
10                 if(nums[i]>nums[i+1])
11                 {
12                     int temp=nums[i+1];
13                     nums[i+1]=nums[i];
14                     nums[i]=temp;
15                     flag=true;}
16             }
17         }while (flag);
18         for(int j=0;j<nums.length;j++) 
19           System.out.print(nums[j]+" ");            
20     }
21 }

4.归并排序

public class mergesort {
    public static void sort1(int[] a,int low, int high, int[] temp)
    {
        if(low<high)
        {
        int mid=(low+high)/2;
        sort1(a,low,mid,temp);
        sort1(a,mid+1,high,temp);
        merge(a,low,mid,high,temp);
        }    
    }
    public static void merge(int[] a,int low, int mid,int high,int[] temp)
    {
        int i=low;
        int j=mid+1;
        int k=0;
        while(i<=mid&&j<=high)
        {
            if(a[i]<a[j])
            temp[k++]=a[i++];
            else temp[k++]=a[j++];
        }
        while(i<=mid)
        {
            temp[k++]=a[i++];
        }
        while(j<=high)
        {
         temp[k++]=a[j++];
        }
         for(i=0; i<k; i++){
                a[low+i] = temp[i];
            }
    }
}

 

posted @ 2018-03-01 16:15  masking_timeflows  阅读(157)  评论(0)  编辑  收藏  举报