First try at graph coloring

Didn't get optimal solution, but got a feasible solution and all
completed quickly - need to add a search tree - greedy, brute force
approach
Knapsack solver

For problems 1-5 got 10/10, but did not run to prove optimality, but
found optimal. Couldn't solve problem 6 although it got an OK value -
7/10.  Branch and bound with sorting, depth first, bound is based on
relaxing integer constraints.