[2D] Random Terrain Generator

So I've been working on a script for a 2D Terrain generator. It isn't one for hills but instead the game is supposed to be inside and I'm having trouble spawning the different floors. The issue is I don't know how to do the inverting the of the code properly. (Also if anyone knows of a better way of doing the entire this please tell me). It spawns just no the way I need it to

void spawnHigherFloors(){

 GameObject stairClone = null;
 GameObject floor = null;
 if(spawning){
     for(int i = 0; i < sizeY -1; i++){
         int stairTemp;
         int stairTemp1;
         int stairPos;
         int posY;
         //Get random position to spawn the stairs
         if(i == 0){
             stairTemp = Random.Range(1, sizeX -1);
             stairPos = stairTemp * 6;
             posY = i * 6;
         }else{
             stairTemp = Random.Range(1, sizeX -1);
             stairTemp1 = sizeX - stairTemp;
             stairPos = stairTemp1 * 6;
             posY = i * 6;
         }
         if(i % 2 == 0){
             /*-------Spawn Even numbered floor--------*/
             //Spawn the staircase
             stairClone = (GameObject) Instantiate(staircase, new Vector3(stairPos, posY, 0), Quaternion.identity);
             stairClone.transform.parent = this.transform;
             int forMath = sizeX -stairTemp -1;
             //Spawn rows of other floors
             for(int j = 0; j < forMath; j++){
                 if(j < forMath -1){
                     float stairX = stairClone.transform.position.x + 8.5f;
                     floor = (GameObject) Instantiate(secondFloor);
                     floor.transform.position = new Vector2(stairX + j * 6, posY + 6);
                 }else if(j == forMath -1){
                     float stairX = stairClone.transform.position.x + 8.5f;
                     floor = (GameObject) Instantiate(endFloor);
                         floor.transform.position = new Vector2(stairX + j * 6, posY + 6);
                 }
                 floor.transform.parent = this.transform;
             }
         }else{
             /*-------Spawn Odd numbered floor--------*/
             stairClone = (GameObject) Instantiate(staircase, new Vector3(stairPos, posY, 0), Quaternion.identity);
             Vector3 theScale = stairClone.transform.localScale;
             theScale.x *= -1;
             stairClone.transform.localScale = theScale;
             stairClone.transform.parent = this.transform;
             int forMath = sizeX -stairTemp -1;
             for(int j = 0; j < forMath; j++){
                 if(j < forMath -1){
                     float stairX = stairClone.transform.position.x - 8.5f;
                     floor = (GameObject) Instantiate(secondFloor);
                     floor.transform.position = new Vector2(stairX - j * 6, posY + 6);
                 }else if(j == forMath -1){
                     float stairX = stairClone.transform.position.x - 8.5f;
                     floor = (GameObject) Instantiate(endFloor);
                     floor.transform.position = new Vector2(stairX - j * 6, posY + 6);
                 }
                 floor.transform.parent = this.transform;
             }
         }
     }
 }

}