complete pic $2$ a$4.$py

pic $1$ is requirement, pic $2$ is a$4.$py$,$ pic $3$ is all the file provided, pic $4$ is expected output

let a$4.$py implement all the requirement and run and test with corrected output

here may some might help:

$*$ 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