Have you ever used the 'bucket fill' tool of paint program to fill a bounded region with a specific colour that is picked from the palette? One such example has been shown below where the area bounded by a circle is being coloured in blue using the same tool. Design the graph model of the problem. Write a simple algorithm to describe how the tool should work in principle. You must justify the reason behind your chosen strategy to solve the problem. $[$Hint: use the concepts of known graph algorithms and design techniques discussed in the class$]$

$[10]$