01 · Read the task
02 · Plan the visits
A₀
p
x
q
Aɢ
B₀
r
s
Bɢ
A
B
A: p → q → Aɢ
B: r → s → Bɢ
t=0
t=1
t=2
t=3
t=4
A
A₀
p
x
q
Aɢ
B
B₀
r
x
s
Bɢ
Both reach x at t=2
◇ Inspection · □ Destination
Illustrative example · one step moves to a neighboring cell or waits. This candidate covers the visits but conflicts at x.