algo2017_week10_Lowestscore

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define ALL(o) (o).begin(),(o).end()
#define fo(n) for(int i=0;i<n;i++)

struct ccc{
    int score;
    char clas;
};

bool cmp( ccc a , ccc b ){ return a.score < b.score; }

int main(){

    int T;

    cin >> T;

    while( T-- ){
        int n , now = -1;
        char c = 'A';

        vector<ccc> p;

        cin >> n;


        fo( n ){
            ccc tmp;
            cin >> tmp.score;
            if( tmp.score < now ) c = 'B';
            now = tmp.score;
            tmp.clas = c;
            p.pb( tmp );
        }

        sort( ALL(p) , cmp );

        fo( 3 ) putchar( p[i].clas );

        puts("");

    }

    return 0;
}