The document discusses three questions related to algorithms and graph problems: 1) For the shortest path problem in directed graphs, the breadth-first search algorithm should be used. When processing vertices and edges, the algorithm needs to compute and update the shortest path from the starting vertex to all other vertices. 2) The second question asks about writing pseudo-code for an exhaustive search algorithm using backtracking to solve the travelling salesman problem and obtain the search tree. 3) The third question discusses either computing the optimal shape of a circuit using a slicing tree algorithm given leaf cell dimensions, or explaining why channel routing is NP-Complete and describing the rotated channel routing algorithm and its results.