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How do I make a pair of math.random() generated numbers not repeat itself?

Asked by

bigbenbennett 18

8 years ago

Edited 8 years ago

I have a very successful mini-game script part that I've worked on which is:

1function InsertColor()
2    for i, v in pairs (game.Players:GetPlayers()) do
3    local PlayerColor = Instance.new("Color3Value")
4    PlayerColor.Parent = v.Character
5    PlayerColor.Name = "Color"
6    PlayerColor.Value = Color3.new(math.random(), math.random(), math.random())
7    TweenColorScreen()
8    end
9end

Each player would be given a random color: eg: 200, 8, 15 which would be a red dominant color

Out of the thousands of permutations possible, how do I make someone in one game not have the same color as someone else so that there could be only one winner?

Thank You.

1 answer

Answered by

plasma_node 343

8 years ago

Edited 8 years ago

First off I would like to say it is important to include the following at the top of your script:

`1`	`math.randomseed(os.time());`

This makes the random numbers even more random.

Then add this: (sorry for weird formatting, I am typing this in web browser and not in an editor)

So basically what you wanna do is store all the random colors in a table, and when you generate a color, you want to check and see if it is already in use.

01local colors = {};
02 
03function IsInTable(Table,Item)
04    for i = 1, #Table, 1 do
05        if (Table[i] == Item) then
06            return true;
07        end
08    end
09    return false;
10end
11 
12function GenrateRandomColor()
13    local color = Color3.new(math.random(),math.random(),math.random());
14    while true do
15        if (IsInTable(colors,color) then
16            -- Another player already has this color
17            color = Color3.new(math.random(),math.random(),math.random());
18        else
19            return color;
20                end
21        end
22end
23 
24function InsertColor()
25    for i, v in pairs (game.Players:GetPlayers()) do
26    local PlayerColor = Instance.new("Color3Value")
27    PlayerColor.Parent = v.Character
28    PlayerColor.Name = "Color"
29    local RandomColor = GenrateRandomColor();
30    PlayerColor.Value = Color3.new(RandomColor.r, RandomColor.g, RandomColor.b)
31    TweenColorScreen()
32    end
33end
 View all 33 lines...

EDIT: I left out a wait(); at line 14 because it is unlikely you will need to iterate more than once to find a unique random color.

So recap:

- Use math.randomseed(os.time()) to ensure your numbers are actually random

- In the extremely unlikely case that a player will get the same three multi digit / decimal random numbers as someone else, keep track of all the colors and check whether or not it has been used yet, if so generate a new one and repeat.

If the color is going to be used on bricks, some extra work will be needed to disambiguate between colors, because Color3 values are collapsed to some BrickColor approximations - i.e. two Color3's which are different could lead to the same BrickColor. duckwit 1404 — 8y

You forgot to add a 'wait' yield inside your iteration @Line 14 RoyallyFlushed 19 — 8y

@sunwatt Good catch, but I left it out because it is highly unlikely that you will need to iterate more than once to generate a new random number plasma_node 343 — 8y

If you want your colors to be bright: local color = Color3.fromHSV(math.random(), 1, 1) l_owbar 1 — 8y

How do I make a pair of math.random() generated numbers not repeat itself?

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