qsort,mergesort,插入排序

    //插入排序 
    int a[n];
    for(int i=2;i<=n;i++)
    {
        int s=a[i];
        int j=i-1;
        while(j&&a[j]>a[i])
        {
            a[j+1]=a[j];
            j--;
        }
        a[j+1]=s;
    } 
    
    
int part(int a[],int low,int high)
{
    int tmp=a[low];
    while(low<high)
    {
        while(low<high&&a[high]>=tmp)
            high--;
        if(low<high)
        {
            a[low]=a[high];
            low++;
        }
        while(low<high&&a[low]<=tmp)
            low++;
        if(low<high)
        {
            a[high]=a[low];
            high--;
        }
    }
    a[low]=tmp;
    return low;
}

void quick_sort(int a[],int low,int high)
{
    int mid;
    if(low<high)
    {
        mid=(low+high)/2;
        mid=part(a,low,high);
        quick_sort(a,low,mid-1);
        quick_sort(a,mid+1,high);
    }
    return ;
}

/************归并************/
void merge(int a[],int low,int high)
{
    int b1=low;
    int mid=(low+high)/2;
    int b2=mid+1;
    int len=high-low+1;
    int *b,k=0;
    b=(int *)malloc(len*sizeof(int));
    while(b1<=mid&&b2<=high)
    {
        if(a[b1]<=a[b2])
            b[k++]=a[b1++];
        else
            b[k++]=a[b2++];
    }
    while(b1<=mid)
        b[k++]=a[b1++];
    while(b2<=high)
        b[k++]=a[b2++];
    for(int i=0;i<len;i++)
        a[low++]=b[i];
    free(b);
}

void merge_sort(int a[],int low,int high)
{
    int mid=(low+high)/2;
    if(low<high)
    {
        merge_sort(a,low,mid);
        merge_sort(a,mid+1,high);
        merge(a,low,high);
    }
    return ;
}