Not repeating random

Questions & Answers
1

I have a code that randomly spawn enemies. How can i make so that the enemies spawed dont repeat?

The code goes like this

IEnumerator SpawnWaves ()
		{
				yield return new WaitForSeconds (startWait);
				while (true) {
						for (int i = 0; i < hazardCount; i++) {
								platform = Random.Range (1, 4);
								
								switch (platform) {
								case 1: 
										Instantiate (prefab1, new Vector3 (0, 6, 0), Quaternion.identity); 
										break;
								case 2:
										Instantiate (prefab2, new Vector3 (0, 6, 0), Quaternion.identity);
										break;
								case 3: 
										Instantiate (prefab3, new Vector3 (0, 6, 0), Quaternion.identity);
										break;
								}

								if (!dead) {
										yield return new WaitForSeconds (Random.Range (spawnWaitStart, spawnWaitEnd));
								}
								if (dead) {
										yield return new WaitForSeconds (100);
								}
						}
				}
		}

Thank you!

2

Well if Answers can stay up long enough I’ll post this (4th attempt!).

This is just example code but it stores a List of three numbers and removes the one picked. When it gets to 0 it rebuilds the list. Only an example so if you can’t work out what to do with the list let me know.

using UnityEngine;
using System.Collections;
using System.Collections.Generic;		// IMPORTANT ADD THIS TO USE LISTS

public class ListTest : MonoBehaviour {

	private List<int> EnemyCountList = new List<int>();
	private int myInt;

	// Use this for initialization
	void Start () {
		LoadEnemyList();
	}
	
	// Update is called once per frame
	void Update () {
	
		myInt = Random.Range (0,EnemyCountList.Count);
		Debug.Log ("How many in the list = " + EnemyCountList.Count + "  Selected Int = " + EnemyCountList[myInt]);

		// instantiate your enemy your enemy number is EnemyCountList[myInt];

		EnemyCountList.Remove(EnemyCountList[myInt]);
		if(EnemyCountList.Count == 0)
			LoadEnemyList();

	}

	void LoadEnemyList()
	{
		EnemyCountList.Add(1);
		EnemyCountList.Add(2);
		EnemyCountList.Add(3);
	}
}

EDIT

OK so you just don’t want the same one as last time but any other order is OK?

private int lastLoaded = 0;


// after platform = Random.Range(1,4)'
  if(platform == lastLoaded)
     int tempRand = Random.Range(0, 2);
     
     switch (platform) {
     case 1:
     		if(tempRand = 0)
     		    platform = 2;
     		    else
     		    platform = 3;
     		    break;
     case 2:
     		if(tempRand = 0)
     		    platform = 1;
     		    else
     		    platform = 3;
     		    break;
     case 3:
     		if(tempRand = 0)
     		    platform = 1;
     		    else
     		    platform = 2;
     		    break;
     }

 // after you instantiate the object
 lastLoaded = platform;

add that and it should stop the previous enemy from instantiating, not tested that code though so watch for errors.

3

Just keep track of what the last one was, and re-randomise if you pick it again next time.

int lastPlatform=-1;
while (true) 
{
    for (int i = 0; i < hazardCount; i++) {
    platform = Random.Range (1, 4);
    while (platform == lastPlatform)
    {
        platform = Random.Range(1,4);
    }
    lastPlatform = platform;
    switch (platform) {

// rest of it as in the question.