MPL Bytecode Compiler Code

23 lines (19 with data), 363 Bytes

;LIBHDR

COUNT=0 ALL=0

TRY(LD,ROW,RD;POSS,P) [
  ROW==ALL ? ++COUNT,[
    POSS=ALL&(-1^(LD:ROW:RD));
    POSS @ [
      POSS=POSS-(P=POSS&-POSS);
      TRY(LD+P<<1,ROW+P,RD+P>>1)
    ]
  ]
]

MAIN(;I) [
  ALL=1;
  I=0; ++I<=12 @ [
    COUNT=0; TRY(0,0,0);
    WRITEF("%I2-QUEENS PROBLEM HAS %I5 SOLUTIONS*N",I,COUNT);
    ALL=2*ALL+1
  ]
]