CF1399E1.Weights Division (easy version)

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题目描述

Easy and hard versions are actually different problems, so we advise you to read both statements carefully.

You are given a weighted rooted tree, vertex 11 is the root of this tree.

A tree is a connected graph without cycles. A rooted tree has a special vertex called the root. A parent of a vertex vv is the last different from vv vertex on the path from the root to the vertex vv . Children of vertex vv are all vertices for which vv is the parent. A vertex is a leaf if it has no children. The weighted tree is such a tree that each edge of this tree has some weight.

The weight of the path is the sum of edges weights on this path. The weight of the path from the vertex to itself is 00 .

You can make a sequence of zero or more moves. On each move, you select an edge and divide its weight by 22 rounding down. More formally, during one move, you choose some edge ii and divide its weight by 22 rounding down ( wi:=wi2w_i := \left\lfloor\frac{w_i}{2}\right\rfloor ).

Your task is to find the minimum number of moves required to make the sum of weights of paths from the root to each leaf at most SS . In other words, if w(i,j)w(i, j) is the weight of the path from the vertex ii to the vertex jj , then you have to make vleavesw(root,v)S\sum\limits_{v \in leaves} w(root, v) \le S , where leavesleaves is the list of all leaves.

You have to answer tt independent test cases.

输入格式

The first line of the input contains one integer tt ( 1t21041 \le t \le 2 \cdot 10^4 ) — the number of test cases. Then tt test cases follow.

The first line of the test case contains two integers nn and SS ( 2n105;1S10162 \le n \le 10^5; 1 \le S \le 10^{16} ) — the number of vertices in the tree and the maximum possible sum of weights you have to obtain. The next n1n-1 lines describe edges of the tree. The edge ii is described as three integers viv_i , uiu_i and wiw_i ( 1vi,uin;1wi1061 \le v_i, u_i \le n; 1 \le w_i \le 10^6 ), where viv_i and uiu_i are vertices the edge ii connects and wiw_i is the weight of this edge.

It is guaranteed that the sum of nn does not exceed 10510^5 ( n105\sum n \le 10^5 ).

输出格式

For each test case, print the answer: the minimum number of moves required to make the sum of weights of paths from the root to each leaf at most SS .

输入输出样例

  • 输入#1

    3
    3 20
    2 1 8
    3 1 7
    5 50
    1 3 100
    1 5 10
    2 3 123
    5 4 55
    2 100
    1 2 409

    输出#1

    0
    8
    3
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