【bzoj2761】[JLOI2011]不重复数字

#include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<set>
using namespace std;

typedef long long LL;

set<LL>S;

LL T;
LL n;
LL x;

int main()
{
scanf("%lld",&T);
while (T--)
{
S.clear();
scanf("%lld",&n);
scanf("%lld",&x);
printf("%lld",x);
S.insert(x);
for (LL i=2;i<=n;i++)
{
scanf("%lld",&x);
if (S.count(x)==0)
{
printf(" %lld",x);
S.insert(x);
}
}
printf("\n");
}
return 0;
}