## 5.a, 5.b, and 5.c

\begin{algorithm}
\begin{algorithmic}
\REQUIRE item = item to insert
\REQUIRE predecessor = linked list item that should precede item
\FUNCTION{insert}{item, predecessor}
\STATE successor $\gets \text{predecessor}_{\text{next}}$
\STATE $\text{item}_{next} \gets$ address of successor
\STATE $\text{item}_{previous} \gets$ address of predecessor
\STATE $\text{predecessor}_{\text{next}} \gets$ address of item
\STATE $\text{successor}_{\text{previous}} \gets$ address of item
\ENDFUNCTION
\STATE
\REQUIRE item = item to delete
\FUNCTION{delete}{item}
\STATE successor $\gets \text{item}_{\text{next}}$
\STATE predecessor $\gets \text{item}_{\text{previous}}$
\STATE $\text{successor}_{\text{previous}} \gets$ address of predecessor
\STATE $\text{predecessor}_{\text{next}} \gets$ address of successor
\ENDFUNCTION
\STATE
\REQUIRE item = item to insert
\REQUIRE index = zero based index indicating where to insert the item
\IF{index = 0}
\STATE $\text{item}_{next} \gets$ address of head
\STATE $\text{head}_{previous} \gets$ address of item
\STATE predecessor $\gets$ head
\FOR{$i \gets 0$ to index - 1}
\STATE predecessor $\gets \text{predecessor}_{next}$