题目
The table below shows the distances, in km, between six data collection points, A, B, C, D, E and F.
| A | B | C | D | E | F | |
|---|---|---|---|---|---|---|
| A | – | 35 | 42 | 55 | 48 | 50 |
| B | 35 | – | 40 | 49 | 52 | 31 |
| C | 42 | 40 | – | 47 | 53 | 49 |
| D | 55 | 49 | 47 | – | 39 | 44 |
| E | 48 | 52 | 53 | 39 | – | 52 |
| F | 50 | 31 | 49 | 44 | 52 | – |
Ferhana must visit each data collection point. She will start and finish at A and wishes to minimise the total distance she travels.
(a) Starting at A, use the nearest neighbour algorithm to obtain an upper bound for the distance Ferhana must travel. Make your method clear.
(b) Starting by deleting B, and all of its arcs, find a lower bound for the distance Ferhana must travel. Make your calculation clear.
(Total 5 marks)
题目中文翻译
下表显示了六个数据收集点 A、B、C、D、E 和 F 之间的距离(单位:km)。
| A | B | C | D | E | F | |
|---|---|---|---|---|---|---|
| A | – | 35 | 42 | 55 | 48 | 50 |
| B | 35 | – | 40 | 49 | 52 | 31 |
| C | 42 | 40 | – | 47 | 53 | 49 |
| D | 55 | 49 | 47 | – | 39 | 44 |
| E | 48 | 52 | 53 | 39 | – | 52 |
| F | 50 | 31 | 49 | 44 | 52 | – |
Ferhana 必须访问每个数据收集点。她将从 A 出发并回到 A,希望最小化总行程距离。
(a) 从 A 出发,使用最近邻算法求出 Ferhana 必须行驶距离的上界。请清楚说明你的方法。
(b) 从删除 B 及其所有弧开始,求出 Ferhana 必须行驶距离的下界。请清楚说明你的计算过程。