Graph-search methods

The methods from Section 10.2.3, which are based on backprojections, can also be applied to this formulation. These methods must initially set $S = {\vec{X}}_G$. If $S$ is initially nonempty, then backprojections can be attempted using the general algorithm in Figure 10.6. Dijkstra's algorithm, as given in Figure 10.8, can be applied to yield a plan that is worst-case optimal.