a[i]<=1000  !!!! 

#include <iostream>
#include <cmath>
#include <cstring>
using namespace std;
 
 int n,b[1003];
 int gcd(int x,int y){
 	return y==0?x:gcd(y,x%y);
 }
 void solve(){
 	int i,j,x,M=0,mx=-1;
 	memset(b,0,sizeof b);
 	for(i=1;i<=n;i++){
 		cin>>x;
		b[x]=max(b[x],i),M=max(M,x);
	 }
 	
 	for(i=1;i<=M;i++)
 	 for(j=1;j<=M;j++){
 	 	 if(gcd(i,j)==1&&b[i]&&b[j]&&b[i]+b[j]>mx) 
		   mx=b[i]+b[j];
	  }
	cout<<mx<<endl;
 }
 signed main(){
 	int cas;
 	cin>>cas;
 	while(cas--) cin>>n,solve();
 }
 

 

posted on 2022-10-26 11:43  towboat  阅读(13)  评论(0)    收藏  举报