KOICOST - Cost
You are given an undirected graph with N vertices and M edges, where the weights are unique.
There is a function Cost(u, v), which is defined as follows:
While there is a path between vertex u and v, delete the edge with the smallest weight. Cost(u,v) is the sum of the weights of the edges that were deleted in this process.
For example, from the graph above (same as the sample input), Cost(2,6) is 2+3+4+5+6 = 20.
Given an undirected graph, your task is to calculate the sum of Cost(u,v) for all vertices u and v, where u < v. Since the answer can get large, output the answer modulo 10^9.
Input
The first line of the input consists of two integers, N and M. (1 <= N <= 100,000, 0 <= M <= 100,000)
The next M lines consists of three integers, u, v, and w. This means that there is an edge between vertex u and v with weight w. (1 <= u, v <= N, 1 <= w <= 100,000)
Output
Output the sum specified in the problem statement.
Example
Input: 6 7
1 2 10
2 3 2
4 3 5
6 3 15
3 5 4
4 5 3
2 6 6 Output: 256
hide comments
utkj97:
2017-06-20 11:02:44
Getting WA on case 20 even with modulo 10^9 :(
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free__bird:
2017-01-28 04:18:01
if getting wa on case 20 ,becauz mode = 1000000000 not 10e9+7
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Wumbolo:
2017-01-05 22:57:06
According to the Merriam-Webster dictionary entry for vertex, vertices and vertexes can be used as the plural of vertex, so verticies is *wrong*. |
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zhzxcool:
2016-12-14 08:53:20
why i got wa on test20?sad :< |
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abhishekrahul:
2016-12-08 17:04:07
best problem of dsu on spoj .............
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cosmopoliton:
2016-05-25 06:51:41
got a wa bcz of this incomplete input statement :(. |
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Augusto:
2016-03-21 23:55:11
Statement is incomplete :/ you need to print the answer modulo 10^9
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bluefa:
2016-03-18 23:56:46
don't use vector . it causes a segment fault |
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Liquid_Science:
2016-02-04 13:49:37
seems to get NZEC in java ,are the constraints correctly specified? |
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fresh:
2015-08-22 15:44:22
@chenzheng
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Added by: | Lawl |
Date: | 2011-06-01 |
Time limit: | 1s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ASM64 |
Resource: | 2011 KOI Regional |