骑士周游

pascal写成的骑士周游，仍有运行时间长（约为10秒左右）的问题，求赐教，以作进一步优化。

uses crt;constN=8;typechessarray=array [1..N,1..N] of integer;steparray=array[1..8,1..2] of integer;varchess:chessarray;step:steparray;procedure init(var _chess:chessarray;var _step:steparray);var i,j:integer;begin        for i:=1 to N do begin                for j:=1 to N do begin                        _chess[i][j]:=0;                end;        end;        _step[1][1]:=-2;_step[1][2]:=-1;        _step[2][1]:=-1;_step[2][2]:=-2;        _step[3][1]:=1;_step[3][2]:=-2;        _step[4][1]:=2;_step[4][2]:=-1;        _step[5][1]:=2;_step[5][2]:=1;        _step[6][1]:=1;_step[6][2]:=2;        _step[7][1]:=-1;_step[7][2]:=2;        _step[8][1]:=-2;_step[8][2]:=1;end;procedure print(_chess:chessarray);var i,j:integer;begin        randomize;        for i:=1 to N do begin                for j:=1 to N do begin                        //1-->14                        textcolor(random(14)+1);                        write(_chess[i][j]:5);                end;                writeln;        end;        writeln;end;procedure test(_step:steparray);var i:integer;begin        for i:=1 to 8 do begin        writeln(_step[i][1]:5,_step[i][2]:5);        end;end;function canJump(x,y:integer):boolean;begin        if (x>=1) and (x<=N) and (y>=1) and (y<=N) and (chess[x][y]=0)        then        begin        canJump:=true;        exit;        end;        canJump:=false;end;procedure backtrack(t,x,y:integer);var i:integer;begin        if t>=N*N then begin                print(chess);                readln;        end        else        begin                for i:=1 to 8 do begin                    if canJump(x+step[i][1],y+step[i][2])=true                    then                    begin                         x:=x+step[i][1];                         y:=y+step[i][2];                         chess[x][y]:=t+1;                         backtrack(t+1,x,y);                         chess[x][y]:=0;                         x:=x-step[i][1];                         y:=y-step[i][2];                    end;                end;        end;end;beginwriteln('waiting...');writeln;init(chess,step);//print(chess);chess[1][1]:=1;backtrack(1,1,1);readln;end.

图为其中的2组解。