Cannot convert float to int when only using floats (C#)

I have a list called layouts that stores 2 dimensional arrays of floats, but whenever I try and access it in the format of layouts[int][float][float] each line gets the 2 identical errors:

Cannot implicitly convert type float' to int'. An explicit conversion exists (are you missing a cast?)

This happens on line 53, 56, 78.

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class floorbuilderv3 : MonoBehaviour {
 
     //room related
     public GameObject[] fourrooms = new GameObject[3];
     public GameObject[] threerooms = new GameObject[3];
     public GameObject[] tworooms = new GameObject[3];
     public GameObject[] onerooms = new GameObject[3];
     public GameObject[] startrooms = new GameObject[1];
 
     //settings
     public float room_distance = 10f;
 
     //flooor related
     int currentfloor = 0;
     public int Size_Increase_Factor = 5;
     List<float[,]> layouts = new List<float[,]>();
     int roomquantity;
     int branchnumb = 0;
     int gridsize;
 
     void Start () {
         transform.position = new Vector3 (0, 0, 0);
         buildnextfloor ();
     }
 
     void buildnextfloor(){
         gridsize = (currentfloor+1) * 20;
         roomquantity = ((currentfloor+1) + (currentfloor+1)) * Size_Increase_Factor;
         float[,] floor = new float[gridsize,gridsize];
         layouts.Add (floor);
         Debug.Log ("gridsize: " + gridsize + ", room quantity: " + roomquantity);
 
         //create unitialized, prioritized floor layout
         creattile (-1, 1,new Vector2(Mathf.FloorToInt (gridsize/2), Mathf.FloorToInt (gridsize/2)));
 
         //initialize the layout
         initialize ();
     }
 /////////////////////////////////////////tile creation////////////////////////////////////    
     void creattile(int remaining, int branch, Vector2 location){
 
         float temp = location.x;
 
         if(remaining > 0)
             return;
         if(location.x > gridsize || location.x < 0 || location.y > gridsize || location.y < 0)
             return;
 
         if(layouts [currentfloor] [location.x, location.y] != 0f)
             return;
 
         layouts [currentfloor] [location.x, location.y] = branch;
         Debug.Log ("placeholder created. grid location: " + location.x + ", " + location.y  + ". branch number: " + branch);
 
         if(remaining == -1){
             int adjacents = Random.Range(2, 4);
             for(int i = 0; i < adjacents; i++){
                 creattile((roomquantity/adjacents),2, expand(location, 0));
             }
         }
         else if(remaining > 2){
             int adjacents = Random.Range(1, 3);
             for(int i = 0; i < adjacents; i++){
                 creattile((remaining/adjacents), branch++, expand(location, 0));
                 branchnumb = branch;
             }
         }
     }
     Vector2 expand(Vector2 location, int iteration){
         iteration ++;
         float x, y;
         x = Mathf.Round (Random.Range ((location.x-1),(location.x+1)));
         y = Mathf.Round (Random.Range ((location.y-1),(location.y+1)));
         if(layouts [currentfloor] [location.x, location.y] != 0 && iteration < 10){
             return expand(location, iteration);}
         return (new Vector2(x, y));
     }
 //////////////////////////////////tile initialization/////////////////////////////////////    
     void initialize(){
         int initializedrooms = 0;
         for(int i = 0; i < branchnumb; i++){
             for(int x = 0; x < gridsize; x++){
                 for(int y = 0; y < gridsize; y++){
                     if(initializedrooms <= roomquantity){
                         if(layouts [currentfloor] [x, y] == i){
                             placeroom(new Vector2(x, y));
                         }
                     }
                 }
             }
         }
     }
     void placeroom(Vector2 gridlocation){
         Debug.Log ("placed room :)");
     }
 }