Program BEEST

This program for the Acorn Atom counts the number of possible Hamilton paths from a certain starting point to all other points.

The program consists of two parts. The second part contains the assembly instructions that generate the core algorithm for finding the Hamilton path. After the secons part is ran, it runs the first part, which contains the interface part of the program. This asks for parameters: length, height x-pos (1..length) and y-pos (1..height) of the starting position. While the program is running, the screen is updated, as the counters for the numbers of hamilton paths to each point are stored in the video RAM. After all the solutions are found, the results are printed in matrix form.

For the input: 6 6 1 1, it outputs

      0   1072      0   1095     0   1770
   1072      0   1420      0  1770      0
      0   1420      0   1240     0    935
   1095      0   1240      0  1180      0
      0   1770      0   1180     0    590
   1770      0    935      0   590      0


TOTAAL :   22144

Part 1

Saved as KL BEEST P1 from 8200-8300.

  190G.d
  200bLINK#FFE3;P.$12"T"T''
  201dIN."L"L,H,A,B
  220F.I=0TOL;F.J=1TOH;F?(I+Z*J)=32;N.;N.
  230F.I=0TO L+1;F?I=V;F?(I+H*Z+Z)=V;N.
  240F.I=0TO H+1;F?(I*Z)=V;F?(1+L+I*Z)=V;N.
  250 ?K=L*H-1;I=#83;?I=0;?C=A+B*Z;F?(?C)=V
  254P.$12
  255F.I=0TO255;I?#8000=I?#A500;N.;LINK#FFE3
  260LINK #A700
  270A=9472;F.I=#8000TO#81FF;I?A=?I;N.
  280F.I=0TOL;F.J=1TOH
  271P.$12;@=7;T=0
  290B=#A500+I+Z*J;B=?B+(B?#100)*256-8224;P.B;T=T+B;N.;P.';N.
  295P.''"TOTAAL :"T
  300LINK#FFE3;G.d
  270aIF?I=#FF G.b

Part 2

Saved as KL BEEST P2 from A000-A200.

   10C=#80;D=#81;E=#82;I=#83
   20K=#84;R=#85;V=42;L=32
   30F=#A500;S=#A600
   31REMZ=16;!R=#FFF00110
   32   Z=32;!R=#FFE00120
   50tDIMLL9;F.J=0TO1;P=#A700
   60[LDX@0;LDA@L
   65:LL0 STA#8000,X;STA#8100,X;INX;BNE LL0;LDA C
   70:LL1
   73 TAX;LDA F+1,X;CMP F-1,X;BNE LL7
   74 LDA F+Z,X;CMP F-Z,X;BNE LL7
   75 TXA; JMP LL4
   79:LL7 TXA;LDY@0
   80:LL2 CLC;ADC R,Y;TAX;LDA F,X;CMP@V;BEQ LL6
   90LDA@V;STA F,X;STX C;LDX I;TYA;STA S,X; INC I;LDA C
  100LDX I;CPX K;BNE LL1
  105 TAX;INC#8000,X;BNE LL4;INC #8100,X
  110:LL4 DEC I;LDX I;CPX@#FF; BNE LL5;RTS
  120:LL5 LDY S,X;TAX;LDA@L;STA F,X
  130:LL6 TXA;SEC;SBC R,Y;INY;CPY @4;BNE LL2;BEQ LL4
  150];N.;Q=LL3
  200 ?18=#82;G.d

Input file for Acorn Atom Emulator

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Acorn Atom Emulator page