Dijkstra?

Write a program that, given a directed multigraph with arcs with positive costs, computes the cost of the second cheapest walk from vertex 0 to every other vertex. Remember that a multigraph may have arcs from $x$ to $x$ , and more than one arc from $x$ to $y$ . Also remember that a walk can repeat vertices and arcs.

Input

Input consists of several cases. Every case begins with the number of vertices $n$ and the number of arcs $m$ , followed by $m$ triples $x$ $y$ $c$ to indicate an arc from $x$ to $y$ with cost $c$ . Assume $2 \le n \le 10^4$ , $0 \le m \le 5n$ , that vertices are numbered from 0 to $n - 1$ , and that every cost $c$ is an integer number between 1 and $10^4$ .

Output

For every case, print the second minimum cost of walking from 0 to the rest of vertices, ordered from 1 to $n - 1$ . If there is no second best walk to some vertex, just print “no”. Print a line with ten dashes at the end of every case.

Problem information

Author: Salvador Roura

Generation: 2026-01-25T10:30:16.978Z