Days of Code [4] - Diagonal Traverse

Hi everyone,

Today I got this problem:

"Given an m x n matrix mat, return an array of all the elements of the array in a diagonal order.
"

Constraints:

• m == mat.length
• n == mat[i].length
• 1 <= m, n <= 104
• 1 <= m * n <= 104
• -105 <= mat[i][j] <= 105

The object is to get the numbers in the array going up and down in diagonal.

Example:

• Input: mat = [[1,2,3],[4,5,6],[7,8,9]]
• Output: [1,2,4,7,5,3,6,8,9]

Another:

• Input: mat = [[5,6]]
• Output: [5,6]

One more:

• Input: mat = [[1,2,3,4],[5,6,7,8]]
• Output: [1,2,5,6,3,4,7,8]

Here is one solution:

Diagonal Traverse