constructor(v) {

    this.num = v;

    this.adjacencyList = new Map();

    this.edgeList = [];

    this.points = [];

    this.visited = [];

    this.path = ""

  }

  addVertex(v) {

    this.adjacencyList.set(v, []);

  }

  addEdge(u, v) {

    this.adjacencyList.get(u).push(v);

    this.adjacencyList.get(v).push(u);

    this.edgeList.push([u, v]);

  }

  getAdjList() {

    let keys = this.adjacencyList.keys();

    let text = "";

    for (let key of keys) {

      let values = this.adjacencyList.get(key);

      let conc = "";

      for (let v in values) {

        let val = values[v];

        if (v == values.length - 1) {

          conc += "(" + val + ")";

        } else {

          conc += "(" + val + "),";

        }

      }

      text += (key + " -> " + conc + "\n");

    }

    text = trim(text);

    //print("Adjacency List\n"+text);

    return text;

  }

  getEdgeList() {

    let text = "[";

    for (let i in this.edgeList) {

      let item = this.edgeList[i];

      if (i == this.edgeList.length - 1) {

        text += "(" + item + ")";

      } else {

        text += "(" + item + "), ";

      }

    }

    text += ']'

    //print("Edge List\n"+text);

    return text;

  }

  display() {

    for (let poi in this.points) {

      let p = this.points[poi];

      noStroke();

      if (this.visited[poi]) {

        fill('green');

      } else {

        fill(0);

      }

      ellipse(p.x, p.y, 10);

      fill(255, 0, 0);

      if (p.x < width / 2) {

        text(int(poi), p.x - 15, p.y + 5);

      } else {

        text(int(poi), p.x + 5, p.y + 5);

      }

    }

    fill(0);

    let edgeList = this.edgeList;

    let points = this.points;

    for (let edge of edgeList) {

      let u0, u1;

      if (edge[0] >= 'A' && edge[0] <= 'Z') {

        u0 = unchar(edge[0]) - 65

      } else {

        u0 = edge[0]

      }

      if (edge[1] >= 'A' && edge[1] <= 'Z') {

        u1 = unchar(edge[1]) - 65

      } else {

        u1 = edge[1]

      }

      //print(edge);

      drawLine(points[u0].x, points[u0].y, points[u1].x, points[u1].y)

      // text(edge[2], (points[u0].x + points[u1].x) / 2, (points[u0].y + points[u1].y) / 2);

    }

  }

  update() {

    this.num = this.adjacencyList.size;

    let n = this.num;

    for (let i = 0; i < n; i++) {

      let angle = i * TWO_PI / n;

      let v = p5.Vector.fromAngle(angle);

      v.mult(-width * 0.3);

      v.add(width / 2, height * 3 / 7);

      this.points.push(v);

    }

    for (let i = 0; i < this.num; i++) {

      this.visited[i] = false;

    }

  }

  runBFS(){

  }

}