Tracing SortedLinkedList

SortedLinkedList<T> keeps its real nodes in ascending order between two sentinels, head and tail, that hold no user value.

Solution

After add(9):

head ───▶ [ ░░░ ] ◀──▶ [ 9 ] ◀──▶ [ ░░░ ] ◀─── tail

After add(4):

head ───▶ [ ░░░ ] ◀──▶ [ 4 ] ◀──▶ [ 9 ] ◀──▶ [ ░░░ ] ◀─── tail

After add(12):

head ───▶ [ ░░░ ] ◀──▶ [ 4 ] ◀──▶ [ 9 ] ◀──▶ [ 12 ] ◀──▶ [ ░░░ ] ◀─── tail

After remove(9):

head ───▶ [ ░░░ ] ◀──▶ [ 4 ] ◀──▶ [ 12 ] ◀──▶ [ ░░░ ] ◀─── tail

After add(7):

head ───▶ [ ░░░ ] ◀──▶ [ 4 ] ◀──▶ [ 7 ] ◀──▶ [ 12 ] ◀──▶ [ ░░░ ] ◀─── tail