Creates graph in form of jagged arrays (as compared to Arraylist) for directed as well as undirected graphs from given set of edges in 0 indexing.

All members of this class are static, so no constructor defined.

public static int[][] makeGraph(int NumberOfNodes, int NumberOfEdges, int[] from, int[] to, boolean undirected)

Returns the adjacency list representation of graph with specified Number of Nodes and Edges and the edges specified in from and to arrays in 0-based indexing. If undirected is set to true, the edges are deemed to be undirected, otherwise directed.

graph[u] is the array of vertices having an edge outgoing from vertex u.

** Constraints **

• 0 \leq from[i], to[i] < NumberOfNodes
• from.length = to.length = NumberOfEdges

** Computational complexity **

• $ O (NumberOfNodes + NumberOfEdges) $

public static int[][][] makeGraphWithEdgeInfo(int NumberOfNodes, int NumberOfEdges, int[] from, int[] to, boolean undirected)

Returns the adjacency list representation of graph with specified Number of Nodes and Edges and the edges specified in from and to arrays in 0-based indexing. If undirected is set to true, the edges are deemed to be undirected, otherwise directed. This method also returns useful information about edge index and edge direction.

graph[u] is the array of tuples [v, idx, direction] where edge indexed idx is between node u and node v and direction takes value either $0$ or $1$.

• If direction is $0$, edge indexed idx is from u to v
• If direction is $1$, edge indexed idx is from v to u

** Constraints **

• 0 \leq from[i], to[i] < NumberOfNodes
• from.length = to.length = NumberOfEdges

** Computational complexity **

• $ O (NumberOfNodes + NumberOfEdges) $