归并排序C语言实现

void swap(int *a,int *b)
{
    int temp=*a;
    *a=*b;
    *b=temp;
}
void merge_array(int a[],int low,int mid,int high,int result[])
{
    int i,j,k;
    i=low;
    j=mid+1;
    k=0;
    while(i<=mid&&j<=high)
    {
        if(a[i]<a[j])
        {
            result[k]=a[i];
            i++;
            k++;
        }
        else
        {
            result[k]=a[j];
            k++;
            j++;
        }
    }
    while(i<=mid)
    {
        result[k]=a[i];
        i++;
        k++;
    }
    while(j<=high)
    {
        result[k]=a[j];
        j++;
        k++;
    }
    for(i=0;i<k;i++)    //注意 需要这一步
    {
        a[low+i]=result[i];  //low+i
    }
}
void merge_sort(int a[],int low,int high,int temp[])
{
	int mid=(low+high)/2;
	if(low<high)
	{
		merge_sort(a,low,mid,temp);
		merge_sort(a,mid+1,high,temp);
		merge_array(a,low,mid,high,temp);
	}
}