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CF1941G.Rudolf and Subway

普及/提高-

通过率：0%

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题目描述

The first line contains an integer tt ( 1≤t≤1041 \le t \le 10^4 ) — the number of test cases.

This is followed by descriptions of the test cases.

The first line of each test case contains two integers nn and mm ( 2≤n≤2⋅105,1≤m≤2⋅1052 \le n \le 2 \cdot 10^5, 1 \le m \le 2 \cdot 10^5 ) — the number of subway stations and the number of direct routes between stations (i.e., graph edges).

This is followed by mm lines — the description of the edges. Each line of the description contains three integers uu , vv , and cc ( 1≤u,v≤n,u≠v,1≤c≤2⋅1051 \le u, v \le n, u \ne v, 1 \le c \le 2 \cdot 10^5 ) — the numbers of the vertices between which there is an edge, and the color of this edge. It is guaranteed that edges of the same color form a connected subgraph of the given subway graph. There is at most one edge between a pair of any two vertices.

This is followed by two integers bb and ee ( 1≤b,e≤n1 \le b, e \le n ) — the departure and destination stations.

The sum of all nn over all test cases does not exceed 2⋅1052 \cdot 10^5 . The sum of all mm over all test cases does not exceed 2⋅1052 \cdot 10^5 .

输入格式

For each testcase, output a single integer — the minimum number of subway lines through which the route from station bb to station ee can pass.

输出格式

The subway graph for the first example is shown in the figure in the problem statement.

In the first test case, from vertex 11 to vertex 33 , you can travel along the path 1→2→31 \rightarrow 2 \rightarrow 3 , using only the green line.

In the second test case, from vertex 11 to vertex 66 , you can travel along the path 1→2→3→61 \rightarrow 2 \rightarrow 3 \rightarrow 6 , using the green and blue lines.

In the third test case, there is no need to travel from vertex 66 to the same vertex, so the number of lines is 00 .

In the fourth test case, all edges of the graph belong to one line, so the answer is 11 .

输入输出样例

  • 输入#1

    5
6 6
1 2 1
2 3 1
5 2 2
2 4 2
4 6 2
3 6 3
1 3
6 6
1 2 1
2 3 1
5 2 2
2 4 2
4 6 2
3 6 3
1 6
6 6
1 2 1
2 3 1
5 2 2
2 4 2
4 6 2
3 6 3
6 6
4 3
1 2 1
1 3 1
4 1 1
2 3
6 7
1 2 43
1 3 34
4 6 43
6 3 43
2 3 43
5 3 43
4 5 43
1 6

    输出#1

    1
2
0
1
1

  • 输入#2

    3
7 9
2 4 1
3 6 1
2 3 5
1 7 1
4 7 1
2 5 4
5 4 4
3 4 1
3 7 1
5 3
6 5
6 5 83691
4 1 83691
5 4 83691
3 2 83691
4 3 83691
5 1
6 7
6 1 83691
6 2 83691
2 5 83691
5 6 83691
2 3 83691
5 4 83574
3 5 83691
1 4

    输出#2

    2
1
2

说明/提示

The subway graph for the first example is shown in the figure in the problem statement.

In the first test case, from vertex 11 to vertex 33 , you can travel along the path 1→2→31 \rightarrow 2 \rightarrow 3 , using only the green line.

In the second test case, from vertex 11 to vertex 66 , you can travel along the path 1→2→3→61 \rightarrow 2 \rightarrow 3 \rightarrow 6 , using the green and blue lines.

In the third test case, there is no need to travel from vertex 66 to the same vertex, so the number of lines is 00 .

In the fourth test case, all edges of the graph belong to one line, so the answer is 11 .

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