顺时针打印矩阵

输入一个矩阵，按照从外向里以顺时针的顺序依次打印出每一个数字，

例如， 如果输入如下矩阵：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

则依次打印出数字

1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10

#!/usr/bin/env python
# -*- coding: utf-8 -*-

class Solution:
    def PrintMatirx(self, matrix):
        if matrix == None:
            return

        if matrix == []:
            return
        Array = []
        start = 0
        columns = len(matrix)
        rows = len(matrix[0])

        while columns > start * 2 and rows > start * 2:
            endX = columns - 1 - start
            endY = rows -1 - start

            for i in range(start, endX+1):
                num = matrix[start][i]
                Array.append(num)

            if start < endY:
                for i in range(start+1, endY+1):
                    num = matrix[i][endX]
                    Array.append(num)

            if start < endX and start < endY:
                for i in range(endX-1, start-1, -1):
                    num = matrix[endY][i]
                    Array.append(num)

            if start < endX and start < endY - 1:
                for i in range(endY-1, start-1, -1):
                    num = matrix[i][endX]
                    Array.append(num)

            start += 1
        return  Array

package main


func PrintMatrix(matrix [][]int) []int {
    var res []int
    n := len(matrix)
    if n==0 {return res}

    m := len(matrix[0])

    nm := n*m
    layer := 0 

    startN, endN, startM, endM := 0, 0, 0, 0

    for nb > 0 {
        startN, endN = layer, n-layer-1
        startM, endM = layer, m-layer-1

        for i := startM; i <= endM && nb > 0; i++ {
            res = append(res, matrix[startN][i])
            nb--
        }

        for i := startN+1; i<=endM && nb>0; i++ {
            res = append(res, matrix[i][startM])
            nb--
        }

        for i := endM-1; i>=startM && nb>0; i++ {
            res = append(res, matrix[endN][i])
            nb--
        }

        for i := endN-1; i>=endN && nb>0; i++ {
            res = append(res, matrix[i][startM])
            nb--
        }
        layer++
    }
    return res
}