pascal n皇后程序，供参考。
{n皇后问题，递归解法，优化解法}
const n=10; {n为皇后个数，在程序中为常数，编译前请调整}
var
b:array[1..n,1..n] of boolean;
i,j:integer;
sum:longint;
procedure next(m:integer); {m表示列,从第一列开始找，直到第n列}
label 999;
var
i:integer;
p,q:integer; {循环变量，分别标识行、列}
find:boolean;
begin {i表示棋盘的行}
if mlt;=n then
for i:=1 to n do begin
{b[i,m]－－以此为基点计算}
find:=false;
for q:=1 to m-1 do if b[i,q] then begin find:=true; goto 999; end; {检查行}
p:=i; q:=m;
while (p-1;=1)and(q-1;=1) do begin {检查左上方}
dec(p);
dec(q);
if b[p,q] then begin find:=true; goto 999; end;
end;
p:=i; q:=m;
while (p+1lt;=n)and(q-1;=1) do begin {检查左下方}
inc(p);
dec(q);
if b[p,q] then begin find:=true; goto 999; end;
end;
if not find then begin
b[i,m]:=true;
next(m+1); {递归}
b[i,m]:=false; {回溯}
end;
999:
end;
if m;n then begin
for p:=1 to n do begin
for q:=1 to n do if b[p,q] then write(q:3);
end;
writeln;
inc(sum);
end
end;
begin
for i:=1 to n do for j:=1 to n do b[i,j]:=false;
sum:=0;
next(1);
if sum;0 then writeln(;sum=;,sum) else writeln(;no solute;);
end.
