topic description
there are N length specifications for raw materials
for example, there are 9 meters and 12 meters
customers need to cut each M root of N specified length L
for example: 1.2m 200m, 1.3m 80root, 1.33m 120root, 1.78m 90root
find out how many pieces of each material are used, how to cut each one, and minimize waste
how should this algorithm be abstracted and analyzed?