排序算法

Posted 2022-12-22 shanbaoxin

public static void kuaipai(int[] arr, int lift, int right) //快速排序
    int l = lift;
    int r = right;
    int p = arr[(lift + right) / 2];
    int temp = 0;
    while (l < r) 
        while (arr[l] < p) 
            l++;
        
        while (arr[r] > p) 
            r--;
        
        if (l >= r) 
            break;
        
        temp = arr[r];
        arr[r] = arr[l];
        arr[l] = temp;

        if (arr[r] == p) 
            l++;
        
        if (arr[l] == p) 
            r--;
        
    
    if (l == r) 
        l += 1;
        r -= 1;
    
    if (lift < r) 
        kuaipai(arr, lift, r);
    
    if (l < right) 
        kuaipai(arr, l, right);
    

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//给定三个颜色的数字，只有0，1，2，然后排序
public static int[] sort1(int[] arr)

    int zero=-1;
    int two=arr.length;
    for(int i=0;i<two;)
        if(arr[i]==1)
            i++;
        else  if(arr[i]==0)
            int a=arr[i];
            arr[i]=arr[++zero];
            arr[zero]=a;
        else
            int a=arr[i];
            arr[i]=arr[--two];
            arr[two]=a;


        
    
    return arr;


///插入排序
public static int[] inster(int[] arr)

    for(int i=1;i<arr.length;i++)
        int a=arr[i];
        int j=i-1;
        while (j>=0&&arr[j]>a)
            arr[j+1]=arr[j];
            j--;

        
        arr[j+1]=a;
    

    return arr;


//冒泡排序
public static int[] maopao(int[] arr)

    for (int i=0;i<arr.length;i++)
        for(int j=0;j<arr.length-i-1;j++)
            if(arr[j]>arr[j+1])
                int temp=arr[j+1];
                arr[j+1]=arr[j];
                arr[j]=temp;
            
        
    
    return arr;

//选择排序
public static int[] xuanze(int[] arr)

    for (int i=0;i<arr.length-1;i++)
        for (int j=i+1;j<arr.length;j++)
            if(arr[i]>arr[j])
                int temp=arr[i];
                arr[i]=arr[j];
                arr[j]=temp;
            
        
    
    return arr;


public static void sort2(int[] arr,int start,int end)
    if(start<end)
        int l=start;
        int r=end;
        int middle=(l+r)/2;
        sort2(arr,l,middle);
        sort2(arr,middle+1,l);
        merger(arr, start,middle, end);
    

private static void merger(int[] arr,int start,int middle,int end)

    int[]  temp=new int[end-start+1];
    int l=start;
    int r=middle;
    int k=0;
    while(l<middle&&r<end)
        if (arr[l] <arr[r]) 
            temp[k++]=arr[l++];
        else 
            temp[k++]=arr[r++];
        
        if(l<middle)
            while (l<middle)
                temp[k++]=arr[l++];
            
        
        if(r<end)
            while (r<end)
                temp[k++]=arr[r++];
            
        
    
    for (int i=0;i<k;i++)
        arr[start++]=temp[i];