1 #include<cstdio>
 2 #include<algorithm>
 3 #include<cmath>
 4 #include<cstring>
 5 #include<set>
 6 
 7 const int MAXN = 1000003;
 8 
 9 inline void read(int &x)
10 {
11     char ch = getchar(),c = ch;x = 0;
12     while(ch < '0' || ch > '9') c = ch,ch = getchar();
13     while(ch <= '9' && ch >= '0') x = (x<<1)+(x<<3)+ch-'0',ch = getchar();
14     if(c == '-') x = -x;
15 }
16 
17 std::set <int> s;
18 int t,n,l,r,ans,num[MAXN];
19 
20 inline int Max(int a,int b)
21 {return a>b?a:b;}
22 
23 int main()
24 {
25     read(t);
26     for(int T = 1;T <= t;++ T)
27     {
28         s.clear();
29         l = 0,r = 1,ans = 0;
30         read(n);
31         for(int i = 1;i <= n;++ i)
32             read(num[i]);
33         while(r <= n)
34         {
35             while(s.find(num[r]) == s.end() && r <= n)
36                 s.insert(num[r++]);
37             ans = Max(ans,r-l-1);
38             while(s.find(num[r]) != s.end()) s.erase(num[++l]);
39         }
40         printf("%d\n",ans);
41     }
42     return 0;
43 }