pic $1$ is requirement, pic $2$ is a$4.$py need to complete followed pic $1$ requirement. pic $3$ is all the file contain, only need to write a$4.$py can be implemented and pass test. pic $4$ and pic $5$ are same type question with requirement and code successfully pass the test, so it might be helpful to use same style and idea to do pic $1-3$ question.

something might important to know :

Some of the edges in the test cases may have a weight of $0\mathrm{.}000.$ You should still treat this as a valid edge.

You can assume the graph doesn't contain any self$-$loops or parallel edges

You can assume the problem is always solvable

You shouldn't need to import any libraries but if you do$,$ it should not trivialise the problem e$.$g$.$ you cannot import network libraries like networkx

For the graph files, the edges in E are formatted so that they are given from node $0$ to upwards $[$u$,$ v$,$ weight$]$ and so u