input: Ethel Matt Chris Jack Bob Sally Bill Tam Jane
data link
+-------------+-------+
0| Ethel | 3 |
+-------------+-------+
1| Matt | 5 | first: 6
+-------------+-------+
2| Chris | 0 | next: 9
+-------------+-------+
3| Jack | 8 |
+-------------+-------+
4| Bob | 2 |
+-------------+-------+
5| Sally | 7 |
+-------------+-------+
6| Bill | 4 |
+-------------+-------+
7| Tam | -1 |
+-------------+-------+
8| Jane | 1 |
+-------------+-------+
9| ??? | ? |
+-------------+-------+
Now we shall execute the following:
delete Jack
delete Tam
delete Bill
add Diane
add Don
There is room for Don but we are unable to reference an unused slot.
Solution - keep a linked list as a stack of available slots in the link
field!