class Node {
    var value: Int
    var visited = false

    init(value: Int = 0) {
        self.value = value
    }
}

class BreadthFirstSearch {
    var queue = [Node]()
    var nodes = [Node]()

    func findNeighbours(adjacenyMatrix: [[Int]], node: Node) -> [Node] {
        var currNodeIndex = -1
        var neighbours = [Node]()

        for i in 0..<nodes.count {
            if nodes[i].value == node.value {
                currNodeIndex = i
                break
            }
        }

        if currNodeIndex != -1 {
            for j in 0..<adjacenyMatrix[currNodeIndex].count {
                if adjacenyMatrix[currNodeIndex][j] == 1 {
                    neighbours.append(nodes[j])
                }
            }
        }

        return neighbours
    }

    func bfs(head: Node? = nil, adjacencyMatrix: [[Int]]) {
        head?.visited = true
        queue.append(head!)

        while !queue.isEmpty {
            let node = queue.remove(at: 0)
            print(node.value)

            let neighbours = findNeighbours(adjacenyMatrix: adjacencyMatrix, node: node)
            for neighbour in neighbours {
                if !neighbour.visited {
                    neighbour.visited = true
                    queue.append(neighbour)
                }
            }
        }
    }
}

let node40 = Node(value: 40)
let node10 = Node(value: 10)
let node20 = Node(value: 20)
let node30 = Node(value: 30)
let node60 = Node(value: 60)
let node50 = Node(value: 50)
let node70 = Node(value: 70)

var example = BreadthFirstSearch()
example.nodes.append(node40)
example.nodes.append(node10)
example.nodes.append(node20)
example.nodes.append(node30)
example.nodes.append(node60)
example.nodes.append(node50)
example.nodes.append(node70)

let adjacency_matrix =
    [
    [0,1,1,0,0,0,0], // Node 1: 40
    [0,0,0,1,0,0,0], // Node 2 :10
    [0,1,0,1,1,1,0], // Node 3: 20
    [0,0,0,0,1,0,0], // Node 4: 30
    [0,0,0,0,0,0,1], // Node 5: 60
    [0,0,0,0,0,0,1], // Node 6: 50
    [0,0,0,0,0,0,0], // Node 7: 70
    ]

example.bfs(head: node40, adjacencyMatrix: adjacency_matrix)