UVA11572

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#include<iostream>
#include<cstring>
#include<cstdio>
#include<string>
#include<algorithm>
#include<queue>
#include<map>
#include<set>
using namespace std;
int a[1000100];
int main(){
	set<int> s;
	int t,mmax,n,ans=0,left,right;
	cin>>t;
	while(t--){
		cin>>n;
		memset(a,0,sizeof(a));
		s.clear();
		for(int i=0;i<n;i++){
			cin>>a[i];
		}
		left=right=ans=0;
		while(right<n){
			while(right<n&&!s.count(a[right])){
				s.insert(a[right++]);
			}
			ans=max(ans,right-left);
			s.erase(a[left++]);
		}
		cout<<ans<<endl;
			}
	return 0;
}