Submission #2865775

---

Source Code Expand

def answer(field)
    field.each do |line|
        puts line.tr('x','.')
    end
    exit 0
end

def isvalid(field)
    8.times do |y|
        8.times do |x|
            if field[y][x] == 'Q'
                (-7..7).each do |i|
                    next if i == 0
                    return false if 0 <= x+i && field[y][x+i] == 'Q'
                    return false if 0 <= y+i && field[y+i] && field[y+i][x] == 'Q'
                    return false if 0 <= y+i && 0 <= x+i && field[y+i] && field[y+i][x+i] == 'Q'
                    return false if 0 <= y+i && 0 <= x-i && field[y+i] && field[y+i][x-i] == 'Q'
                end
            end
        end
    end
    return true
end

def update(field)
    8.times do |y|
        8.times do |x|
            if field[y][x] == 'Q'
                (-7..7).each do |i|
                    field[y][x+i] = 'x' if 0 <= x+i && field[y][x+i] == '.'
                    field[y+i][x] = 'x' if 0 <= y+i && field[y+i] && field[y+i][x] == '.'
                    field[y+i][x+i] = 'x' if 0 <= y+i && 0 <= x+i && field[y+i] && field[y+i][x+i] == '.'
                    field[y+i][x-i] = 'x' if 0 <= y+i && 0 <= x-i && field[y+i] && field[y+i][x-i] == '.'
                end
            end
        end
    end
end

def solve(field, qcnt)
    answer(field) if qcnt == 8
    8.times do |y|
        8.times do |x|
            if field[y][x] == '.'
                new_field = field.map{|e|e.clone}
                new_field[y][x] = 'Q'
                update(new_field)
                solve(new_field, qcnt+1)
            end
        end
    end
end


@field = 8.times.map{gets.chomp}
unless isvalid(@field)
    puts "No Answer"
    exit 0
end
update(@field)

solve(@field, 3)
puts "No Answer"

Submission Info

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