Water Flow Problem Statement

Given a matrix A with dimensions 'N' x 'M', where each cell represents the height of water in that location, determine the coordinates from which water can flow to both the Pacific and Atlantic oceans. Water can only flow horizontally or vertically to neighboring cells that have a height less than or equal to the current cell.

Explanation:

The matrix boundaries act as ocean borders with the Pacific on the left and top, and the Atlantic on the right and bottom. Find all coordinates where water can flow to both oceans. Return the coordinates in lexicographical order.

Input:

The first line of input contains an integer 'T', the number of test cases.
For each test case, the first line contains two integers, 'N' and 'M', representing the number of rows and columns in the matrix.
The following 'N' lines each contain 'M' space-separated integers representing the matrix 'A'.

Output:

For each test case, the output begins with an integer 'K' representing the number of coordinates.
Each of the next 'K' lines contains the coordinates in the format: row column.

Example:

Input:
1
3 3
1 2 2
3 4 3
2 3 1
Output:
3
0 1
1 1
2 1

Constraints:

• 1 ≤ T ≤ 50
• 1 ≤ N, M ≤ 104
• 1 ≤ N*M ≤ 104
• 1 ≤ A[i][j] ≤ 109
• Time Limit: 1 second

Note:

Implement the given function. Printing is already handled.