BFS paths from 0
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Gửi bài giải
Điểm:
1,00 (OI)
Giới hạn thời gian:
1.0s
Giới hạn bộ nhớ:
256M
Input:
stdin
Output:
stdout
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Ngôn ngữ cho phép
C, C++, Java, Kotlin, Pascal, PyPy, Python, Scratch
Given a directed graph, print a path from vertex 0 to every other vertex. When there is more than one vertex that can be visited next, prioritize visiting the smaller vertex first.
For each vertex v (1 ≤ v < n):
- If there exists a path from vertex
0tov, print one such path. - If multiple paths exist, print the path determined by the traversal order.
- If vertex
vis unreachable from vertex0, print-1.
Input
- The first line consists of two positive integers, the number of vertices
n(0 < n ≤ 10^5) and the number of edgesm(0 < m ≤ 2 × 10^5). - Then there are
mlines, each containing two integersuandv(u, v < 10^5), representing a directed edge fromutov.
Output
For each vertex v (1 ≤ v < n):
- Print one line containing a path from vertex
0to vertexv. - Vertices on the path must be separated by
->. - If no path exists, print
-1.
Example Input:
4 4
0 3
3 2
1 0
0 1
Example Output:
0->1
0->1->3->2
0->1->3
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