| Agri-Net |
|Time Limit: 1000ms, Special Time Limit:2500ms, Memory Limit:65536KB |
| Total submit users: 30, Accepted users: 28 |
| Problem 10685 :
No special judgement
| Farmer John has been elected mayor
of his town! One of his campaign promises was to bring internet connectivity to
all farms in the area. He needs your help, of course. |
Farmer John ordered a high speed connection for his farm and is going to share
his connectivity with the other farmers. To minimize cost, he wants to lay the
minimum amount of optical fiber to connect his farm to all the other farms.
Given a list of how much fiber it takes to connect each pair of farms, you must
find the minimum amount of fiber needed to connect them all together. Each farm
must connect to some other farm such that a packet can flow from any one farm to
any other farm.
The distance between any two farms will not exceed 100,000.
| The input includes several cases.
For each case, the first line contains the number of farms, N (3 <= N <= 100).
The following lines contain the N x N conectivity matrix, where each element
shows the distance from on farm to another. Logically, they are N lines of N
space-separated integers. Physically, they are limited in length to 80
characters, so some lines continue onto others. Of course, the diagonal will be
0, since the distance from farm i to itself is not interesting for this problem.|
| For each case, output a single
integer length that is the sum of the minimum length of fiber required to
connect the entire set of farms. |
0 4 9 21
4 0 8 17
9 8 0 16
21 17 16 0