David W. answered 11/02/17
Tutor
4.7
(90)
Experienced Prof
River
Start Finish
Step 1:
A1, A2, C1, C2
---C1, C2 ----->
A1, A2 C1, C2
Step 2:
<----C1------
A1, A2, C1 C2
Step 3:
----A1----->
A2, C1 A1, C2
Step 4:
<----C2-----
A2, C1, C2 A1
[note: getting each adult across and getting the boat back is a milestone]
Step 5:
----C1, C2---->
A2 A1, C1, C2
Step 6:
<----C2------
A2, C2 A1, C1
Step 7:
----A2---->
C2 A1, A2, C1 [both adults have crossed]
Step 8:
<----C1----
C1, C2 A1, A2
Step 9:
----C1, C2---->
none A1, A2, C1, C2 (with boat)