Algorithms Concepts

Proof

Two steps of correctness proof

  • feasibility: satisfy the constraints

  • optimality: better than any other solution

To prove feasibility, we just check whether the constraints are satisfied. To prove optimality, there are many approaches.

  • \(OPT\) gradually approaches out solution \(S\), e.g. by induction

Say our solution will not overshoot by saying that it is a feasible solution.

Simplification

Try to think some reasonable assumptions to transform the original problem setting into a simpler setting. If the optimal solution under the new setting corresponds to an optimal solution under the original setting, then the transformation is valid.

Graph Basics

  • Forest: a graph that is not connected and have no cycles

Charging Scheme

Reference