Statement

Given an $m \times n$ binary matrix, mat, find the distance from each cell to the nearest $0$. The distance between two adjacent cells is $1$. Cells to the left, right, above, and below the current cell will be considered adjacent.

Constraints:

• $1 \leq$ mat.row , mat.col$\leq 50$

• $1 \leq$ mat.row * mat.col $\leq 2500$

• mat[i][j] $\in \{0, 1\}$

• There is at least one $0$ in mat.

Example