A11268 | Rudolf and Subway
时间限制1s
内存限制256MB
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题目描述
The first line contains an integer $t$ ( $1 \le t \le 10^4$ ) — the number of test cases.
This is followed by descriptions of the test cases.
The first line of each test case contains two integers $n$ and $m$ ( $2 \le n \le 2 \cdot 10^5, 1 \le m \le 2 \cdot 10^5$ ) — the number of subway stations and the number of direct routes between stations (i.e., graph edges).
This is followed by $m$ lines — the description of the edges. Each line of the description contains three integers $u$ , $v$ , and $c$ ( $1 \le u, v \le n, u \ne v, 1 \le c \le 2 \cdot 10^5$ ) — 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 $b$ and $e$ ( $1 \le b, e \le n$ ) — the departure and destination stations.
The sum of all $n$ over all test cases does not exceed $2 \cdot 10^5$ . The sum of all $m$ over all test cases does not exceed $2 \cdot 10^5$ .
This is followed by descriptions of the test cases.
The first line of each test case contains two integers $n$ and $m$ ( $2 \le n \le 2 \cdot 10^5, 1 \le m \le 2 \cdot 10^5$ ) — the number of subway stations and the number of direct routes between stations (i.e., graph edges).
This is followed by $m$ lines — the description of the edges. Each line of the description contains three integers $u$ , $v$ , and $c$ ( $1 \le u, v \le n, u \ne v, 1 \le c \le 2 \cdot 10^5$ ) — 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 $b$ and $e$ ( $1 \le b, e \le n$ ) — the departure and destination stations.
The sum of all $n$ over all test cases does not exceed $2 \cdot 10^5$ . The sum of all $m$ over all test cases does not exceed $2 \cdot 10^5$ .
输入格式
For each testcase, output a single integer — the minimum number of subway lines through which the route from station $b$ to station $e$ 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 $1$ to vertex $3$ , you can travel along the path $1 \rightarrow 2 \rightarrow 3$ , using only the green line.
In the second test case, from vertex $1$ to vertex $6$ , you can travel along the path $1 \rightarrow 2 \rightarrow 3 \rightarrow 6$ , using the green and blue lines.
In the third test case, there is no need to travel from vertex $6$ to the same vertex, so the number of lines is $0$ .
In the fourth test case, all edges of the graph belong to one line, so the answer is $1$ .
In the first test case, from vertex $1$ to vertex $3$ , you can travel along the path $1 \rightarrow 2 \rightarrow 3$ , using only the green line.
In the second test case, from vertex $1$ to vertex $6$ , you can travel along the path $1 \rightarrow 2 \rightarrow 3 \rightarrow 6$ , using the green and blue lines.
In the third test case, there is no need to travel from vertex $6$ to the same vertex, so the number of lines is $0$ .
In the fourth test case, all edges of the graph belong to one line, so the answer is $1$ .
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
The subway graph for the first example is shown in the figure in the problem statement.
In the first test case, from vertex $1$ to vertex $3$ , you can travel along the path $1 \rightarrow 2 \rightarrow 3$ , using only the green line.
In the second test case, from vertex $1$ to vertex $6$ , you can travel along the path $1 \rightarrow 2 \rightarrow 3 \rightarrow 6$ , using the green and blue lines.
In the third test case, there is no need to travel from vertex $6$ to the same vertex, so the number of lines is $0$ .
In the fourth test case, all edges of the graph belong to one line, so the answer is $1$ .
In the first test case, from vertex $1$ to vertex $3$ , you can travel along the path $1 \rightarrow 2 \rightarrow 3$ , using only the green line.
In the second test case, from vertex $1$ to vertex $6$ , you can travel along the path $1 \rightarrow 2 \rightarrow 3 \rightarrow 6$ , using the green and blue lines.
In the third test case, there is no need to travel from vertex $6$ to the same vertex, so the number of lines is $0$ .
In the fourth test case, all edges of the graph belong to one line, so the answer is $1$ .
C++ 编辑器
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评测结果：Accepted