读得太慢，开快读。
```cpp
ios_base::sync_with_stdio(false);
cin.tie(0);cout.tie(0);
```
[加在主函数开头](https://www.luogu.com.cn/record/155288834)
by yx666 @ 2024-04-11 12:44:46
@[qq1508020550](/user/334389) 将输入输出分别用scanf与printf就行
by xiaozhang6666 @ 2024-04-11 15:05:25
@[yx666](/user/825020) 谢谢大佬
by qq1508020550 @ 2024-04-11 15:14:33
@[xiaozhang6666](/user/978778) 谢谢大佬
by qq1508020550 @ 2024-04-11 15:14:47
@[qq1508020550](/user/334389) 试试这个
```
#include <bits/stdc++.h>
#define int long long
using namespace std;
struct node
{
int num,id;
}a[50005],b[50005];
bool cmp(node x,node y)
{
if(x.num!=y.num) return x.num<y.num;
return x.id<y.id;
}
bool cmp1(node x,node y)
{
return x.id<y.id;
}
main()
{
ios::sync_with_stdio(0);cin.tie(0),cout.tie(0);
int t;
cin>>t;
a[0].num=-1;
while(t--){
memset(b,0,sizeof(b));
int n,cnt=0;
cin>>n;
for(int i=1;i<=n;i++) cin>>a[i].num,a[i].id=i;
sort(a+1,a+1+n,cmp);
for(int i=1;i<=n;i++){
if(a[i].num!=a[i-1].num) b[++cnt].num=a[i].num,b[cnt].id=a[i].id;
}
sort(b+1,b+1+cnt,cmp1);
for(int i=1;i<=cnt;i++) cout<<b[i].num<<" ";
cout<<"\n";
}
return 0;
}
```
by kervinyan @ 2024-05-07 19:08:16