刷题-- 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.

看到这道题目的时候我的直观想法是递归。我把一行或一列的情况择了出来，总感觉这样不太好…

# -*- coding:utf-8 -*-
class Solution:
    # matrix类型为二维列表，需要返回列表
    def printMatrix(self, matrix):
        # write code here
        array = []

        if matrix:
            m = len(matrix)
            n = len(matrix[0])

            if m == 1:
                i = 0
                for j in range(n):
                    array.append(matrix[i][j])

                return array
            elif n == 1:
                j = 0
                for i in range(m):
                    array.append(matrix[i][j])

                return array
            else:
                i, j, k, t, p = 0, n - 1, m - 1, 0, 1
                for j in range(n):
                    array.append(matrix[i][j])

                for k in range(i + 1, m):
                    array.append(matrix[k][j])

                for t in range(j - 1, -1, -1):
                    array.append(matrix[k][t])

                for p in range(k - 1, i, -1):
                    array.append(matrix[p][t])

                subArray = self.printMatrix([matrix[q][t + 1:j] for q in range(p, k) if matrix[q][t + 1:j]])
                if subArray:
                    return array + subArray
                else:
                    return array

下面是剑指offer上的思路：

# -*- coding:utf-8 -*-
class Solution:
    # matrix类型为二维列表，需要返回列表
    def printMatrix(self, matrix):
        # write code here
        array = []

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

            //→_→反正我觉得我想不到这个结束条件
            while (rows > start * 2) and (columns > start * 2):
                endX = rows - 1 - start
                endY = columns - 1 - start

                for i in range(start, endY + 1):
                    array.append(matrix[start][i])

                if start < endX:
                    for j in range(start + 1, endX + 1):
                        array.append(matrix[j][endY])

                if (start < endY) and (start < endX):
                    for k in range(endY - 1, start - 1,  -1):
                        array.append(matrix[endX][k])

                if (start < endX - 1) and (start < endY):
                    for t in range(endX - 1, start, -1):
                        array.append(matrix[t][start])

                start += 1

            return array