题目
Problem
(a) Explain what is meant by the term ‘path’.
(2)
Figure 1 represents a network of roads. The number on each arc represents the length, in km, of the corresponding road. Piatrice wishes to travel from A to J.
(b) Use Dijkstra’s algorithm to find the shortest path Piatrice could take from A to J. State your path and its length.
(6)
Piatrice needs to return from J to A via G.
(c) Find the shortest path Piatrice could take from J to A via G and state its length.
(2)
题目中文翻译
(a) 解释术语”路径”的含义。
图 1 表示一个道路网络。每条弧上的数字表示对应道路的长度（单位：km）。Piatrice 希望从 A 到 J。
(b) 使用 Dijkstra 算法找到 Piatrice 从 A 到 J 可以走的最短路径。写出路径及其长度。
Piatrice 需要经 G 从 J 返回 A。
(c) 找到 Piatrice 经 G 从 J 到 A 可以走的最短路径并写出其长度。