ChuVanKhanh's blog

By ChuVanKhanh, history, 18 months ago, In English

Giving an undirected weighted graph of n (n <= 1e5) vertices , n — 1 edges and an positive integer k (k <= 1e9). Count the number of pairs (i , j) that i < j and the weight of the path from i to j is not bigger than k.

Input the first line contain n and k the following n — 1 lines each contains three positive integer u , v , w (u , v <= n , w <= 1e9)

Output the number of pairs (i , j) that the weight of the path from i to j is not bigger than k.

Sample

INPUT
6 8
1 2 2 
2 3 4
2 5 1
4 5 3
5 6 5

OUTPUT
14

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By ChuVanKhanh, history, 21 month(s) ago, In English

Hi everyone, I've encountered a rather difficult problem for me, I hope you guys can give me some suggestions. The problem is as follows for a positive integer S (S <= 1e9), find how many ways to decompose the number S into the sum of positive integers whose greatest common divisor is 1.(Two sets of numbers that are vin permutations are also counted as different).

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By ChuVanKhanh, history, 2 years ago, In English

My solution is to count the divisors of (a*b)^2 but a, b <= 1e6. In addition the problem has testcase <= 1e6. Can you help me?

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