The Locker Problem
Student
Student
Student
Student
Student
Student
Student
#7
#10
#8
#4
#2
#9
#6
#3
#5
starts
starts
starts
starts
starts
Student
#20
#12
#13
#14
#15
#16
#17
#18
#19
#11
with
with
with
with
with
starts
Locker
#1
Locker
Locker
Locker
Locker
opens
with7842
10
9
Locker
63
and
5and
every
and
and
and
and
and
changes
changes
changes
closes
changes
changes
changes
changes
20
11
12
13
14
15
16
17
18
19
locker
andevery
every
door
every
changes
every
every
every
every
every
second
seventh
eighth
fourth
ninth
sixth
third
fifth
tenth
it door
door
door
door
door
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
1
1
2
1
2
1
2
3
1
2
1
2
3
4
1
2
43
1
2
1
2
3
1
2
3
4
1
2
64
5
1
2
3
1
2
1
2
3
4
1
2
3
4
54
1
2
3
1
2
64
1
2
3
5
1
2
1
2
5
6
3
4