Shortest Path in a Binary Matrix Problem Statement

Given a binary matrix of size N * M where each element is either 0 or 1, find the shortest path from a source cell to a destination cell, consisting only of 1s. If no such path exists, return -1.

Note:

• The matrix is 0-indexed.
• You can move in 4 directions (up, down, left, right) from any cell.
• The path length is the number of 1s on the path.
• The source cell is always initialized as 1.

Example:

Input:

1 0 1
1 1 1
1 1 1
SOURCEX = 0, SOURCEY = 0, DESTX = 0, DESTY = 2

Output:

5

Explanation:

Several valid paths exist, such as:

X 0 X
X X X
1 1 1

Another valid path:

X 0 X
X 1 X
X X X

The shortest path from the source cell (0,0) to destination cell (0,2) consisting of 1s is of length 5.

Constraints:

• 1 ≤ N ≤ 500
• 1 ≤ M ≤ 500
• MAT[i] = {0, 1}
• 0 ≤ SOURCEX ≤ N - 1
• 0 ≤ SOURCEY ≤ M - 1
• 0 ≤ DESTX ≤ N - 1
• 0 ≤ DESTY ≤ M - 1
• MAT[SOURCEX][SOURCEY] = 1
• Time Limit: 1 sec

Input:

The first line contains two integers 'N' and 'M', denoting the matrix dimensions.
Next 'N' lines contain 'M' space-separated integers, representing the matrix.
Following them, a line specifies 'SOURCEX' and 'SOURCEY'.
The final line specifies 'DESTX' and 'DESTY'.

Output:

A single integer representing the length of the shortest valid path from source to destination.

Note:

No need to print anything. Implement the function to solve the problem.