Mesh Generation(C#): Mesh has jagged edges plus strange rendering

I want to make my program generate a 3D graph of a formula within certain boundaries and a certain resolution. The problem with the code is that when I run it, the mesh has strange jagged edges and the triangles aren't connecting properly making the mesh render very strangely(rendering on both sides).

Here is the code(C#):

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class CustomGraph : MonoBehaviour {
 
     string formula;
     List<Vector3>verts;//Stores the list of vertices for the mesh
     List<int>tris;//Stores the list of triangles for the mesh
     List<Vector2> uvs;//Stores the list of uvs for the mesh
     MeshFilter graphMesh = null;
 
     void Start()
     {
         verts = new List<Vector3> ();
         tris = new List<int> ();
         uvs = new List<Vector2> ();
         graphMesh = gameObject.GetComponent<MeshFilter> ();
         if(graphMesh == null)
         {
             Debug.LogError("Graph does not have MeshFilter");
         }
         GenerateGraph(0,10,1f,"x");
     }
 
     void GenerateGraph(int start, int end, float res, string form)
     {
         ShuntingYard (form);
         CalculateVerts (start, end, res);
         CalculateTris (end-start);
         UpdateGraph ();
     }
 
     void ShuntingYard(string form)
     {
         //Does whatever it does and saves it to the variable 'formula'
         //Isn't needed for testing
     }
 
     void CalculateVerts(int start, int end, float res)
     {
         verts.Clear ();
         for(float z = start; z <= end; z += res)
         {
             for(float x = start; x <= end; x += res)
             {
                 Vector3 current_point = new Vector3();
                 current_point.x = x;
                 current_point.z = z;
                 current_point.y = CalculateY(x,z);
                 verts.Add (current_point);
                 uvs.Add (new Vector2(x,z));
             }
         }
     }
 
     float CalculateY(float x, float z)
     {
         //Calculates y using the ShuntingYard algorithm and returns the value
         //For testing, the formula will be manually input
         return x;
     }
 
     void CalculateTris(int width)
     {
         tris.Clear ();
         for(int index =0; index < verts.Count-width; index++)
         {
             if(index == 0)
             {
                 tris.Add(index);
                 tris.Add(index+1);
                 tris.Add (index+width);
             }
             else if(index % width == 0)
             {
                 tris.Add(index);
                 tris.Add(index+1);
                 tris.Add (index+width);
             }
             else if((index + 1) % width == 0)
             {
                 tris.Add(index);
                 tris.Add(index + width);
                 tris.Add (index + width - 1);
             }
             else
             {
                 tris.Add(index);
                 tris.Add(index + width);
                 tris.Add (index + width - 1);
                 tris.Add(index);
                 tris.Add(index+1);
                 tris.Add (index+width);
             }
         }
     }
 
     void UpdateGraph()
     {
         Mesh finalgraph = new Mesh ();
         finalgraph.vertices = verts.ToArray ();
         finalgraph.triangles = tris.ToArray ();
         finalgraph.uv = uvs.ToArray ();
         finalgraph.RecalculateBounds ();
         finalgraph.RecalculateNormals ();
         graphMesh.mesh.Clear ();
         graphMesh.mesh = finalgraph;
 
     }
 
 }
 

I've been messing around with the CalculateTris() method and that seems to be the problem, but I just can't figure out what it is. Please let me know if there are any clarifications that are needed. Thanks!