Causal Broadcast Deliver Check

Problem

Check whether a broadcast message can be delivered under causal order.

local_clock is the current version vector and message is [sender, vector]. A message from sender is deliverable when its vector count for sender is exactly local_clock[sender] + 1 and every other component is at most the local count, meaning all dependencies arrived first.

Return True or False.

Hint

The sender's own counter must advance by exactly one, and all other counts must already be known.

Test cases

case 1

in: [[0,0,0],[0,[1,0,0]]]

expected: true

case 2

in: [[1,0,0],[0,[1,0,0]]]

expected: false

case 3

in: [[0,0,0],[1,[0,1,0]]]

expected: true

case 4

in: [[0,0,0],[0,[2,0,0]]]

expected: false

case 5

in: [[0,1,0],[2,[0,1,1]]]

expected: true

Starter codePython

def causal_check(local_clock, message):
    # Your code here
    pass

5 test cases · run your code against them in the editor