代码

 #include <stdlib.h>
void merge(int arr[],int begin,int mid,int end){
    int *tmp = (int*)malloc(sizeof(int)*(end-begin));
    int i=begin,j=mid,k=0;
    for(;i<mid&&j<end;tmp[k++]=(arr[i]<arr[j]?arr[i++]:arr[j++]));
    for(;i<mid;tmp[k++]=arr[i++]);
    for(;j<end;tmp[k++]=arr[j++]);
    for(i=begin,k=0;i<end;arr[i++]=tmp[k++]);
    free(tmp);
}
void sort1(int arr[],int begin,int end){
	if(end-begin<2)return;
	int mid=(begin+end)>>1;
	sort1(arr,begin,mid);
	sort1(arr,mid,end);
	merge(arr,begin,mid,end);
}
void sort(unsigned *a, int n) {
	sort1(a,0,n);
}

评测结果