Vector Clock Comparison

Two events in a distributed system can be ordered with vector clocks. Given two vector clocks a and b, classify their order:

• equal: all entries are equal
• before: for all i, a[i] <= b[i] and at least one a[i] < b[i]
• after: for all i, a[i] >= b[i] and at least one a[i] > b[i]
• concurrent: neither is before/after the other

Return one of: "before", "after", "concurrent", "equal".

Function signature

func CompareVectorClocks(a, b []int) string

Example

a = [1,2,3]
b = [1,3,3]
output = "before"

Constraints

• 0 <= len(a) <= 100000
• 0 <= a[i], b[i]

Notes

• If lengths differ, missing entries are treated as 0.
• Vector clocks detect concurrency; Lamport clocks do not.