Given a set of pixels forming a closed loop, aka a triangle in paint, write a program which would colour the region (fill colour) based on the location of click on the screen. If clicked outside will colour everything outside the triangle and if clicked inside would colour inside the triangle, Given api's as getcolor( ) & setcolor( ) based on coordinate.

Question

Accepted Answer

Program to fill a closed loop (triangle) with color based on click location.

Use a flood fill algorithm to color the region inside the triangle.
Check if the click location is inside or outside the triangle using point-in-polygon algorithm.
If clicked outside, color everything outside the triangle using a different color.
Use the getcolor() and setcolor() APIs to interact with the pixel colors.
Handle edge cases like overlapping triangles or concave polygons.

Accepted Answer

Apply bfs starting from the position of click in the pixels matrix.

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