#include<cstdio>#include<vector>#include<cstdlib>usingnamespace std;intmain(){int K;scanf("%d",&K);for(int i =0, N, flag; i < K;++i ){scanf("%d",&N);
flag =1;
vector<int>A(N +1),visited(N +1);for(int j =1; j <= N;++j ){scanf("%d",&A[j]);if( visited[ A[j]]++)
flag =0;}for(int j =1; j <= N && flag;++j )for(int k = j +1; k <= N && flag;++k )if(abs( j - k )==abs( A[j]- A[k]))
flag =0;printf("%s\n", flag ?"YES":"NO");}}