Kosaraju Example

We trace Kosaraju on this graph: $1 \to 2 \to 3 \to 1$, $3 \to 4$. First DFS starting from $1$: visit $1$, then $2$, then $3$, then $4$. Finish order (pushed to stack): $[4, 3, 2, 1]$ (stack top is $1$). Transpose graph: $1 \leftarrow 2 \leftarrow 3 \leftarrow 1$, $3 \leftarrow 4$.

Second DFS: pop $1$, explore $\{1, 2, 3\}$ (one SCC). Pop $4$, explore $\{4\}$ (another SCC). Result: Two SCCs found: $\{1, 2, 3\}$ and $\{4\}$.