class GraphBuilder{

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

int[][] graph = new int[NumberOfNodes][];

int[] outdegree = new int[NumberOfNodes];

for(int i = 0; i< NumberOfEdges; i++){

outdegree[from[i]]++;

if(undirected)outdegree[to[i]]++;

}

for(int i = 0; i< NumberOfNodes; i++)graph[i] = new int[outdegree[i]];

for(int i = 0; i< NumberOfEdges; i++){

graph[from[i]][--outdegree[from[i]]] = to[i];

if(undirected)graph[to[i]][--outdegree[to[i]]] = from[i];

}

return graph;

}

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

int[][][] graph = new int[NumberOfNodes][][];

int[] outdegree = new int[NumberOfNodes];

for(int i = 0; i< NumberOfEdges; i++){

outdegree[from[i]]++;

if(undirected)outdegree[to[i]]++;

}

for(int i = 0; i< NumberOfNodes; i++)graph[i] = new int[outdegree[i]][];

for(int i = 0; i< NumberOfEdges; i++){

graph[from[i]][--outdegree[from[i]]] = new int[]{to[i], i, 0};

if(undirected)graph[to[i]][--outdegree[to[i]]] = new int[]{from[i], i, 1};

}

return graph;

}

}