螺旋矩阵

local arr =
{
    {1, 2,  3, 4, 5, 6},
    {7, 8,  9, 10,11,12},
    {13,14, 15,16,17,18},
    {19,20, 21,22,23,24},
    {25,26, 27,28,29,30},
    {31,32, 33,34,35,36}
}
local output
local printRotation = function(a,b,row,col)
    if a == row then    --一行
        for j = b,col do
            if not output then
                output = tostring(arr[a][j])
            else
                output = output..","..tostring(arr[a][j])
            end
        end
    elseif b == col then --一列
        for i = a,row do
            if not output then
                output = tostring(arr[i][b])
            else
                output = output..","..tostring(arr[i][b])
            end
        end
    else
        --上边界
        for j = b,col - 1 do
            if not output then
                output = tostring(arr[a][j])
            else
                output = output..","..tostring(arr[a][j])
            end
        end
        --右边界
        for i = a,row - 1 do
            output = output..","..tostring(arr[i][col])
        end
        --下边界
        for j = col,b + 1,-1 do
                output = output..","..tostring(arr[row][j])
        end
        --左边界
        for i = row,a + 1,-1 do
            output = output..","..tostring(arr[i][b])
        end
    end
end
local a = 1
local b = 1
local row = #arr
local col = #arr[1]
while a <= row and b <= col do
    printRotation(a,b,row,col)
    a = a + 1
    b = b + 1
    row = row - 1
    col = col - 1
end
print("printRotationOutPut=====",output)

输出：

printRotationOutPut=====	1,2,3,4,5,6,12,18,24,30,36,35,34,33,32,31,25,19,13,7,8,9,10,11,17,23,29,28,27,26,20,14,15,16,22,21