Devise a scan line algorithm for filling the interior regions with the given input set of vertices having scan lines at $y=7,y=5$ and $y=2.$

$\backslash$table$[[$Vertex$,1,2,3,4,5,6,7,8,9,10,11,12,13],[x,1,1,2,2,5,5,7,7,5,5,3,3,1],[Y,1,5,5,7,7,5,5,1,1,2,2,1,1]]$