c-归并排序

#include <stdio.h>
#include <stdlib.h>
//合并两个序列
void mergearray(int a[],int first,int mid,int last,int temp[])
{
    int i=first,j=mid+1;
    int m=mid,n=last;
    int k=0;
while(i<=m&&j<=n)
{
    if(a[i]<a[j])
        temp[k++]=a[i++];
    else
        temp[k++]=a[j++];
}
while(i<=m)
{
    temp[k++]=a[i++];
}
while(j<=n)
{
    temp[k++]=a[j++];
}
for(i=0;i<k;i++)
    a[first+i]=temp[i];
}
void mergesort(int a[],int first,int last,int temp[])
{
    if(first<last)
    {
        int mid=(first+last)/2;
        mergesort(a,first,mid,temp);//左边有序
        mergesort(a,mid+1,last,temp);//右边有序
        mergearray(a,first,mid,last,temp);
    }
}
void main()
{
    int temp[10]={0};
    int a[10]={2,6,8,4,1,3,7,9,5,0};
    mergesort(a,0,10-1,temp);
    for(int i=0;i<10;i++)
    {
        printf("%d",a[i]);
    }
}