題目鏈接：

https://www.lydsy.com/JudgeOnline/problem.php?id=2761

題目大意：

思路：

set

 1 #include<bits/stdc++.h>
 2 #define IOS ios::sync_with_stdio(false);//不可再使用scanf printf
 3 #define Max(a, b) ((a) > (b) ? (a) : (b))//
 
禁用於函數，會超時
 4 #define Min(a, b) ((a) < (b) ? (a) : (b))
 5 #define Mem(a) memset(a, 0, sizeof(a))
 6 #define Dis(x, y, x1, y1) ((x - x1) * (x - x1) + (y - y1) * (y - y1))
 7 #define MID(l, r) ((l) + ((r) - (l)) / 2)
 8 #define lson ((o)<<1)
 9 #define rson ((o)<<1|1)
10 #define Accepted 0
11
 
 #pragma comment(linker, "/STACK:102400000,102400000")//棧外掛
12 using namespace std;
13 inline int read()
14 {
15     int x=0,f=1;char ch=getchar();
16     while (ch<‘0‘||ch>‘9‘){if (ch==‘-‘) f=-1;ch=getchar();}
17     while (ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
18     return x*f;
19 }
20 typedef long
 
 long ll;
21 const int MOD = 1000000007;//const引用更快，宏定義也更快
22 const double eps = 1e-10;
23 const double pi = acos(-1);
24 const int INF = 0x3f3f3f3f;
25 const int maxn = 10000 + 10;
26 
27 set<int>s;
28 int main()
29 {
30     int T;
31     scanf("%d", &T);
32     while(T--)
33     {
34         int n, x, first = 1;
35         scanf("%d", &n);
36         s.clear();
37         while(n--)
38         {
39             scanf("%d", &x);
40             if(s.count(x))continue;
41             s.insert(x);
42             if(first)first = 0;
43             else printf(" ");
44             printf("%d", x);
45         }
46         puts("");
47     }
48 }

BZOJ 2761 不重復數字 set