题解

#include<iostream>
using namespace std;
int a[1005];
int n;
void mergesort(int a[],int l,int r){
	if(l==r) return;
	int mid=(l+r)/2;
	mergesort(a,l,mid);
	mergesort(a,mid+1,r);
	int i=l,j=mid+1,k=l;
	int tmp[1005];
	while(i<=mid&&j<=r)
		if(a[i]<=a[j]) tmp[k++]=a[i++];
		else tmp[k++]=a[j++];
	while(i<=mid) tmp[k++]=a[i++];
	while(j<=r) tmp[k++]=a[j++];
	for(int i=l;i<=r;i++) a[i]=tmp[i];
}
int main(){
	cin>>n;
	for(int i=1;i<=n;i++) cin>>a[i];
	mergesort(a,1,n);
	for(int i=1;i<=n;i++) cout<<a[i]<<" ";
	return 0;
}