q09FloodFill
solutions.q09FloodFill
Question 9 [PY]
Given an image \(M\in\mathbb{Z}^{H\times W}\) represented as a grid (or matrix) of \(H\times W\) of integers, where \(m_{ij}\) represents the pixel value of \(i\)-th row, \(j\)-th column.
-
WAP to flood-fill colour \(\kappa\) starting at pixel at \(r\)-th row and \(c\)-th column.
-
Reflect on the relative merits of using BFS/DFS for the process.
Flood Fill
- Flood fill is a process to change the colour of a contiguous region, by starting with a given source pixel and expanding along the neighbours until a boundary is hit.
- Region is defined by colour of the start pixel.
- Neighbours shares a boundary (either vertically or horizontally).
- A neighbour with colour different than that of the start pixel is deemed to be a boundary; it’s colour is left untouched!
Functions:
| Name | Description |
|---|---|
q09FloodFill |
Args: |
q09FloodFill(M, k, r, c)
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
M
|
List[List[int]]
|
A list of \(H\) lists of \(W\) integer values each representing colour at pixel \((i,j)\). |
required |
k
|
int
|
Target colour. |
required |
r
|
int
|
Row of the start pixel. |
required |
c
|
int
|
Col of the start pixel. |
required |