题单：归并排序

样例 #1

样例输入 #1样例输出 #1

2 5
4 7
2 4 5 7
1 3
2 6
1 2 3 6
1 2 2 3 4 5 6 7
1 2 2 3 4 5 6 7

#include<bits/stdc++.h>
using namespace std;
int n,a[1000005],tmp[1000005]; 
void mearge(int l,int mid,int r)
{
	int i=l,j=mid+1,k=l;
	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];
		cout<<a[i]<<" ";
	}
	cout<<endl;
}
void mearge_sort(int l,int r)
{
	if(l==r)
	{
		return ;
	}
	int mid=(l+r)/2;
	mearge_sort(l,mid);
	mearge_sort(mid+1,r);
	mearge(l,mid,r);
}
int main(){
	cin>>n;
	for(int i=1;i<=n;i++) cin>>a[i];
	mearge_sort(1,n);
	for(int i=1;i<=n;i++)
	{
		cout<<a[i]<<" ";
	}
	return 0;
}