package main

type (
	AdjacencyMatrix map[int]map[int]int

	Graph struct {
		X map[int]Vector
		E []map[int]Vector
		L map[int]int
		A AdjacencyMatrix
	}
)

func (A AdjacencyMatrix) Modify(u, v, w int) {
	if A[u] == nil {
		A[u] = make(map[int]int)
	}
	A[u][v] = w
}

func MakeGraph() Graph {
	G := Graph{
		make(map[int]Vector),
		make([]map[int]Vector, 3),
		make(map[int]int),
		make(AdjacencyMatrix),
	}
	for i := 0; i < 3; i++ {
		G.E[i] = make(map[int]Vector)
	}
	return G
}

func (G Graph) AddNode(u int, V Vector, l int) {
	G.X[u] = V
	G.L[u] = l
}

func (G Graph) AddEdge(u, v int) {
	G.A.Modify(u, v, 1)
	G.A.Modify(v, u, -1)
}