The font traversal of a matrix

Title Description: give you a matrix containing M x n elements (m rows, n columns), to find the font traversal of the matrix.

Examples: For the following matrices:

[
[1, 2, 3, 4],
[5, 6, 7, 8],
[9, 10, 11, 12]
]

return [1, 2, 5, 9, 6, 3, 4, 7, 10, 11, 8, 12]

First of all, explain the meaning of the topic first. In fact, the entire matrix is traversed at a 45-degree angle, obliquely upward, alternating diagonally downward. Take the example, as shown in:

Arrows represent the order of traversal.

So, we can design a Boolean up to indicate whether it should be up or down now, but the difficulty with this program is the up conversion.

At first, up = True, go up, and when do you change direction?

To facilitate the explanation, we set the line designator to I, the column label is J:

1. When I < 0 or J >= N, change direction downwards. But the marking also needs to adjust, if J < N, indicates can go right, then J does not change, so i = i-1 (row return), if J >= N (cannot go right), j = j-1 (column homing), I = I-2 (from 8 to 12 in the example)

2. When I >= m or J < 0, change direction to go up, the same way, adjust the label (the difficulty of this problem lies in the adjustment of the label, to analyze carefully)

To figure out the principle, you can give the code:

Class Solution: # @param: a matrix of integers # @return: A list of integers def printzmatrix (self, Matrix):        result, Count = [], 0 if len (matrix) = = 0:return result m, n = Len (Matrix), Len (Matrix[0]) I, j = 0, 0 while count < m * N:up = true when up = = True and I >= 0 and J <            N:result.append (Matrix[i][j]) I-= 1 J + = 1 count + = 1  # can go to the right if J <= n-1: i + = 1 # can't go right, it's just down the road else:i                + = 2 J-= 1 up = False when up = False and I < m and J >= 0:            Result.append (Matrix[i][j]) i + = 1 J-= 1 count + = 1 # can go down                If I <= m-1: J + = 1 # can not go down, you can only go to the right Else:j + 2 I-= 1 returnResult # Write your code here 

The font traversal of a matrix