Need formula to cut and weld steel pipe with minimal waste.

We are working on a project where we need 7 pieces at 45', 5 pieces at 50', 2 pieces at 35', and 1 piece at 20'. The lengths we are working with to make this are : 49.1 with a mid-weld at 39.8.
31.7
20.8 with a mid-weld at 11.2
20 with a mid-weld at 10.9
18 with a mid-weld 8.2
17.8
27.2
35.5
32.5
35.3
35.8
If anyone can make a formula that can calculate the best way to cut, weld, and cut again with minimal waste that would be great. Not only will this help with this project, but it will help us to be able to do more projects like this on the fly. Thanks in advance!

EDIT
Basically what we want is something to take the original lengths, cut off footage, then add it on another piece and then repeat until we have the desired number of pieces and footages. Thanks!