% https://code.google.com/codejam/contest/4314486/dashboard
% Problem A. Senate Evacuation
% Round 1C, Problem A, in Picat, by Afa Zhou

import util.

main =>
    T = read_line().to_int(),
    foreach (TC in 1..T)
        N = read_line().to_int(),
        Ps = [to_int(Token) : Token in read_line().split()],
        dc(TC,N,Ps)                        
    end.

dc(TC,N,Ps) =>
    PLs = [Pair : Pair in zip(Ps,1..N)].sort_down(),
    Total = sum(Ps),
    printf("Case #%w: ", TC),
    ev(PLs,Total).

ev([],_l) => nl.
ev([{0,_}|_],_) => nl.
ev([{P1,L1},{P2,L2}|PLs],Total),
    PLs1 = [{P1-1,L1},{P2-1,L2}|PLs].sort_down(),
    safe(PLs1,Total-2)
 =>
    pr(L1),pr(L2),print(' '),
    ev(PLs1,Total-2).    
ev([{P,L}|PLs],Total) =>
    pr(L),print(' '),
    (P-1 == 0 -> PLs1 = PLs; PLs1 = [{P-1,L}|PLs].sort_down()),
    ev(PLs1,Total-1).

safe(PLs,Total) =>
    foreach({P,_} in PLs)
         P =< Total div 2
    end.

pr(L) =>
    C = ord('A')+L-1,
    print(chr(C)).
    

    
    

picat-lang.org