public HalfEdgeMesh(Mesh mesh) {
        float[] pos = mesh.getPos();
        float[] norms = mesh.getNorms();
        int[] inds = mesh.getInds();

        halfEdges = new ArrayList<>();
        vertices = new ArrayList<>();

        // Hint: You will need multiple passes of the arrays to set up
        // each geometry object. A suggestion is to:
        //   (1) Create vertex list
        for(int i = 0 ; i < pos.length ; i+=3){
            Vertex v = new Vertex(i/3, pos[i], pos[i+1], pos[i+2], norms[i], norms[i+1], norms[i+2]);
            vertices.add(v);
        }

        System.out.println("FIRST INDICES: "+ inds[0]+","+inds[1]+","+inds[2]+","+inds[3]+","+inds[4]);
        System.out.println("vertex id1: "+vertices.get(inds[0]).getId());
        System.out.println("vertex id2: "+vertices.get(inds[1]).getId());
        System.out.println("vertex id3: "+vertices.get(inds[2]).getId());
        System.out.println("vertex id4: "+vertices.get(inds[3]).getId());
        System.out.println("vertex id5: "+vertices.get(inds[4]).getId());
        //   (2) Create half edge list and set faces
        for(int i = 0; i < inds.length ; i+=3){

            HalfEdge ed1 = new HalfEdge();
            HalfEdge ed2 = new HalfEdge();
            HalfEdge ed3 = new HalfEdge();

            ed1.setNextV(vertices.get(inds[i+1]));
            ed2.setNextV(vertices.get(inds[i+2]));
            ed3.setNextV(vertices.get(inds[i]));

            vertices.get(inds[i]).setEdge(ed1);
            vertices.get(inds[i+1]).setEdge(ed2);
            vertices.get(inds[i+2]).setEdge(ed3);

            Face fc = new Face(ed1);
            ed1.setlFace(fc);
            ed2.setlFace(fc);
            ed3.setlFace(fc);

            ed1.setNextE(ed2);
            ed2.setNextE(ed3);
            ed3.setNextE(ed1);

            halfEdges.add(ed1);
            halfEdges.add(ed2);
            halfEdges.add(ed3);

        }


        //   (3) Set flip edges
        HashMap<String,HalfEdge> halfEdgeMap = new HashMap<String,HalfEdge>();
        //make key value pair of vertices and corresponding halfedge
        //string is composed of vertex ID
        for(int i = 0 ; i<inds.length ; i+=3){
            String str1 = Integer.toString(vertices.get(inds[i]).getId())+","+Integer.toString(vertices.get(inds[i+1]).getId());
            String str2 = Integer.toString(vertices.get(inds[i+1]).getId())+","+Integer.toString(vertices.get(inds[i+2]).getId());
            String str3 = Integer.toString(vertices.get(inds[i+2]).getId())+","+Integer.toString(vertices.get(inds[i]).getId());

            HalfEdge ed1 = halfEdges.get(i);
            HalfEdge ed2 = halfEdges.get(i+1);
            HalfEdge ed3 = halfEdges.get(i+2);

            halfEdgeMap.put(str1,ed1);
            halfEdgeMap.put(str2,ed2);
            halfEdgeMap.put(str3,ed3);
        }

        for(int i = 0 ; i< inds.length; i+=3){
            String str1 = Integer.toString(vertices.get(inds[i]).getId())+","+Integer.toString(vertices.get(inds[i+1]).getId());
            String str2 = Integer.toString(vertices.get(inds[i+1]).getId())+","+Integer.toString(vertices.get(inds[i+2]).getId());
            String str3 = Integer.toString(vertices.get(inds[i+2]).getId())+","+Integer.toString(vertices.get(inds[i]).getId());

            String flipStr1 = Integer.toString(vertices.get(inds[i+1]).getId())+","+Integer.toString(vertices.get(inds[i]).getId());
            String flipStr2 = Integer.toString(vertices.get(inds[i+2]).getId())+","+Integer.toString(vertices.get(inds[i+1]).getId());
            String flipStr3 = Integer.toString(vertices.get(inds[i]).getId())+","+Integer.toString(vertices.get(inds[i+2]).getId());

            halfEdgeMap.get(str1).setFlipE(halfEdgeMap.get(flipStr1));
            halfEdgeMap.get(str2).setFlipE(halfEdgeMap.get(flipStr2));
            halfEdgeMap.get(str3).setFlipE(halfEdgeMap.get(flipStr3));
        }
        // student code starts here

        System.out.println("vertices: "+ vertices.size());
        //System.out.println("HALF EDGES: "+ halfEdges);


    }