LeetCode 785 Is Graph Bipartite? - Input Format

The input is already an adjacency list. graph[i] gives you all neighbors of node i directly. No need to build the graph yourself. For example, if graph = [[1,3],[0,2],[1,3],[0,2]], then: - Node $0$ connects to nodes $1$ and $3$ - Node $1$ connects to nodes $0$ and $2$ - Node $2$ connects to nodes $1$ and $3$ - Node $3$ connects to nodes $0$ and $2$ This is a $4$-cycle: $0$-$1$-$2$-$3$-$0$.

Since $4$ is even, this graph should be bipartite.