N = 8 -- 棋盘大小
function isplaceok(a, n, c)
for i = 1, n - 1 do
if (a[i] == c) or
(a[i] - i == c - n) or
(a[i] + i == c + n) then
return false
end
end
return true
end
-- 打印棋盘
function printsolution(a)
for i = 1, N do
for j = 1, N do
io.write(a[i] == j and "X" or "-", " ")
end
io.write("\n")
end
io.write("\n")
end
function addqueen(a, n)
if n > N then
printsolution(a)
else
for c = 1, N do
if isplaceok(a, n, c) then
a[n] = c
addqueen(a, n + 1)
end
end
end
end
addqueen({}, 1)