An adjacency list is an array $A$ of separate lists.
Each element of the array $A_{i}$ is a list, which contains all the vertices that are adjacent to vertex $i$.
- $A_{1}\rightarrow2\rightarrow3\rightarrow5$
- $A_{2}\rightarrow1\rightarrow3$
- $A_{3}\rightarrow1\rightarrow2\rightarrow4\rightarrow5$
- $A_{4}\rightarrow3\rightarrow5$
- $A_{5}\rightarrow1\rightarrow3\rightarrow4$