PROCEDURE BREADTH(VAR   N:INTEGER);

VAR I,J:INTEGER;

BEGIN
  K:=1;
  Q[ 1 ]:=1;
  WH:=2;
  FOR I:=1 TO N DO WRITE(P[I,Q[1]]=0);
    WHILE Q[ 1 ]<>0 DO
      BEGIN
        FOR I:=1 TO N DO
          SEARCH [ I,K ] := ALPHA [ Q[I] ];
        K:=K+1;
        RH:=Q[ 1 ];
        FOR I:=1 TO N DO
          IF P[ RH,I ]=1 THEN BEGIN
            Q[WH]:=I;
            WH:=WH+1;
            FOR J:=1 TO N DO P[J,I]:=0
          END;
        FOR I:=1 TO N DO Q[I]:=Q[ I+1 ];
        WH:=WH-1
      END;
END;