An example from other discussions:

input:
4 3 12
1 2 5
1 3 4
3 4 4

output:
YES

displays the correct answer.
Tell me more examples, please.

In the algorithm, I check loops, two-way roads, cycles, and then look for a way longer than necessary.

UPD: WA#18

Edited by author 20.03.2019 19:17