QOJ.ac

QOJ

Time Limit: 1 s Memory Limit: 128 MB Total points: 100

#3118. Dark roads

统计

Economic times these days are tough, even in Byteland. To reduce the operating costs, the government of Byteland has decided to optimize the road lighting. Till now every road was illuminated all night long, which costs 1 Bytelandian Dollar per meter and day. To save money, they decided to no longer illuminate every road, but to switch off the road lighting of some streets. To make sure that the inhabitants of Byteland still feel safe, they want to optimize the lighting in such a way, that after darkening some streets at night, there will still be at least one illuminated path from every junction in Byteland to every other junction.

What is the maximum daily amount of money the government of Byteland can save, without making their inhabitants feel unsafe?

Input Specification

The input file contains several test cases. Each test case starts with two numbers $m$ and $n$, the number of junctions in Byteland and the number of roads in Byteland, respectively. Input is terminated by $m=n=0$. Otherwise, $1 ≤ m ≤ 200000$ and $m-1 ≤ n ≤ 200000$. Then follow $n$ integer triples $x$, $y$, $z$ specifying that there will be a bidirectional road between $x$ and $y$ with length $z$ meters ($0 ≤ x, y < m$ and $x ≠ y$). The graph specified by each test case is connected. The total length of all roads in each test case is less than $2^{31}$.

Output Specification

For each test case print one line containing the maximum daily amount the government can save.

Sample Input

7 11
0 1 7
0 3 5
1 2 8
1 3 9
1 4 7
2 4 5
3 4 15
3 5 6
4 5 8
4 6 9
5 6 11
0 0

Sample Output

51

Discussions

About Discussions

The discussion section is only for posting: Editorials, General Discussions (problem-solving strategies, alternative approaches), and Off-topic conversations.

This is NOT for reporting issues! If you want to report bugs or errors, please use the Issues section below.

Open Discussions 0
No discussions in this category.

Issues

About Issues

If you find any issues with the problem (statement, scoring, time/memory limits, test cases, etc.), you may submit an issue here. A problem moderator will review your issue.

Guidelines:

  1. This is not a place to publish discussions, editorials, or requests to debug your code. Issues are only visible to you and problem moderators.
  2. Do not submit duplicated issues. Submitting multiple issues may cause your account to be banned.
  3. Issues must be filed in English or Chinese only.
Active Issues 0
No issues in this category.
Closed/Resolved Issues 0
No issues in this category.