Left Center Right (LCR) code golf

Question

At a party, I was introduced to the game LCR. Now it's not a great game as there's no skill but only random chance. But it got me thinking, I could code this, and I made a quick program in R to model the game.

Rules of the game modified from Wikipedia to match how we played:

Each player receives at least 3 chips. Players take it in turn to roll three six-sided dice, each of which is marked with "L", "C", "R" on one side, and a single dot on the three remaining sides. For each "L" or "R" thrown, the player must pass one chip to the player to their left or right, respectively. A "C" indicates a chip to the center (pot). A dot has no effect.

If a player has fewer than three chips left, they are still in the game but their number of chips is the number of dice they roll on their turn, rather than rolling all three. When a player has zero chips, they pass the dice on their turn, but may receive chips from others and take their next turn accordingly. The winner is the last player to put chips into the center.

Contest: write a program in your language of choice that takes input for the number of players and the number of starting chips and simulates a game of LCR, showing the state of the game after each player has rolled.

For example, a game might be output as:

[[[3,3,3,3],0],[[1,4,3,4],0],[[1,4,3,4],0],[[1,4,1,4],2],[[1,4,1,2],4],
[[0,4,1,3],4],[[0,3,2,3],4],[[0,3,0,3],6],[[0,3,1,1],7],[[0,3,1,1],7],
[[2,0,1,1],8],[[2,0,0,1],9],[[2,0,0,0],10],[[0,1,0,0],11],
[[1,0,0,0],11],[[1,0,0,0],11],[[1,0,0,0],11],[[0,0,0,0],12]]

ht: JonathanAllan

The output doesn't have to look exactly like this, but it should be easy to discern the dice roll, how many chips each player has, and how many chips the centre has for each turn.

It's code golf so the shortest code wins.

Answer 1

Emacs Lisp, 279 bytes

(defmacro n(i)`(incf(nth ,i c)))
(defun f(p s)(g(let((a'(0)))(dotimes(i p)(push s a))(princ a))0 p))
(defun g(c v p)(dotimes(i(min(nth v c)3))(decf(nth v c))(case(random 6)(0(n(mod(1- v)p)))(1(n(mod(1+ v)p)))(2(n p))(t(n v))))(princ c)(or(eq(-sum c)(nth p c))(g c(mod(1+ v)p)p)))

Use this function as (f 4 3).

Better readable version:

(defmacro n (i) `(incf (nth ,i c)))

(defun f(p s)
  (g
   (let ((a '(0)))
     (dotimes (i p)
       (push s a))
     (princ a))
   0
   p))

(defun g (c v p)
  (dotimes (i (min (nth v c) 3))
    (decf (nth v c))
    (case (random 6)
      (0 (n (mod (1- v) p)))
      (1 (n (mod (1+ v) p)))
      (2 (n p))
      (t (n v))))
    (princ c)
    (or (eq (-sum c) (nth p c))
    (g c (mod (1+ v) p) p)))

Output example:

(3 3 3 3 0)(1 4 3 4 0)(2 2 4 4 0)(2 2 2 5 1)(4 2 2 3 1)(2 2 2 4 2)(2 1 3 4 2)(2 2 0 4 4)(2 2 0 4 4)(1 2 0 4 5)(2 1 0 4 5)(2 1 0 4 5)(2 1 1 3 5)(0 1 1 3 7)(1 0 1 3 7)(1 0 1 3 7)(1 0 3 1 7)(1 0 3 1 7)(1 0 3 1 7)(1 1 2 1 7)(1 1 3 0 7)(0 1 3 0 8)(1 0 3 0 8)(1 1 1 1 8)(1 1 2 0 8)(0 1 2 1 8)(0 1 2 1 8)(0 1 1 1 9)(0 1 1 1 9)(0 1 1 1 9)(0 1 1 1 9)(0 1 1 1 9)(0 1 1 0 10)(0 1 1 0 10)(0 0 1 0 11)(0 0 1 0 11)(0 0 1 0 11)(0 0 1 0 11)(0 0 1 0 11)(0 0 0 0 12)

Answer 2

Java 8, 281 277 275 274 253 bytes

Version which outputs the same state when a turn player has 0 chips left:

p->n->{java.util.Arrays A=null;int c[]=new int[p],i=0,t,r,s=1,u,f=9;for(A.fill(c,n);s>0;f=0,System.out.print(A.toString(c)))for(t=c[++i%p],t=t>3?3:t;t-->f;r*=Math.random(),c[i%p]-=1-r/3,s=c[u=(i+r-1+p)%p]+=1-r&1-r/4,c[u]=s<0?0:s,s=A.stream(c).sum())r=6;}

Starts with the third player in the array.

Try it online.

Version which skips players with 0 chips left (274 bytes):

p->n->{java.util.Arrays A=null;int c[]=new int[p],i=p,t,r,s=1,u,f=9;for(A.fill(c,n);s>0;f=0,System.out.print(A.toString(c))){for(t=c[i%p],t=t>3?3:t;t-->f;r*=Math.random(),c[i%p]-=1-r/3,s=c[u=(i+r-1+p)%p]+=1-r&1-r/4,c[u]=s<0?0:s)r=6;for(s=A.stream(c).sum();s>0&c[++i%p]<1;);}}

Starts at the first player in the array.

Try it online.

-7 bytes thanks to @OlivierGrégoire.

Explanation (of the second version):

p->n->{                      // Method with two integer parameters and no return-type
  java.util.Arrays A=null;   //  Create a static Arrays-object to save bytes
  int c[]=new int[p],        //  Integer-array with chips of each player (0 by default)
      i=p,                   //  Index integer, starting at the amount of players
      t,                     //  Temp integer to roll 3 dice
      r,                     //  Temp integer for the dice-result
      s=1,u,                 //  Temp integers (and `s` is also the total-sum integer)
      f=9;                   //  Flag integer, starting at a single digit above 3
  for(A.fill(c,n);           //  Give each player in the array the chips
      s>0                    //  Loop as long as the total-sum is not 0 yet
      ;                      //    After every iteration:
       f=0,                  //     Set the flag to 0
       System.out.print(A.toString(c))){
                             //     Print the current state
    for(t=c[i%p],            //   Set `t` to the current player's chips
        t=t>3?3:t;           //   If this is larger than 3: set it to 3 instead
        t-->f                //   Loop that many times (1, 2, or 3)
                             //   (the flag is used to skip this loop the first iteration,
                             //   so we can print the initial state)
        ;                    //     After every iteration:
         r*=Math.random(),   //      Roll the dice in the range [0,5]
         c[i%p]-=r<3?        //      If the dice-roll is 0, 1 or 2:
                  1          //       Remove a chip from this player
                 :0,         //      Else: Leave the chip-amount the same
         s=c[u=(i+r-1+p)%p]  //      If the dice-roll is 0, go to the player left
                             //      If the dice-roll is 2, go to the player right
             +=1-r&1-r/4,    //       And add a chip to this player
         c[u]=s<0?0:s)       //      Change negative amount of chips to 0
      r=6;                   //    Reset the dice-roll to 6 so we can roll again
    for(s=A.stream(c).sum(); //   Calculate the total sum of the chips of the players
        s>0&                 //   If this sum is larger than 0:
         c[++i%p]<1;);}}     //    Determine the next player in line with at least 1 chip

Answer 3

Python 2, 159 148 bytes

from random import*
n,c=input()
g=[c]*n;i=0
while sum(g):exec"r=randrange(6);g[i]-=1;g[i-[0,1,~-n][max(0,r-3)]]+=r>0;"*min(3,g[i]);i=(i+1)%n;print g

Try it online!

Prints all players chips after every roll

Answer 4

Jelly, 39 bytes

<sup>+2 to fix repetition behaviour (¡ must be preceded by a nilad so «3Ḣ$ -> ⁸FḢ«3)

If we can define the output lists to be rotated to have the chips belonging to the player who acted previously at the left we can do away with the right-most 6 bytes for 33 bytes (however, in my opinion, it is somewhat awkward to read that).</sup>

ẋµ’1¦‘.,2ŻX¤¦$¹Ø.X¤?⁸FḢ«3¤¡ṙ1µSпṙ"JC$$

A dyadic Link accepting chips-per-player on the left and number-of-players on the right which yields a list of players chip counts as at the start of the game and after each turn (including turns where 0 chips forces a pass).

Try it online!

How?

Each player in turn, up to three times, depending on their chip count, flips a coin. When a player flips heads they do nothing but if they flip tails they then roll a three sided die losing a chip to L, C or R. (Note that 0 flips when a player has 0 chips is equivalent to passing.)
This is repeated until the sum of the players chips is 0.
The implementation rotates the players left by one place each turn and then rotates the resulting states back to all be aligned as if they were not.

ẋµ’1¦‘.,2ŻX¤¦$¹Ø.X¤?⁸«3Ḣ¤¡ṙ1µSпṙ"JC$$ - Link: chipsPerPlayer, C; numberOfPlayers, P
ẋ                                      - repeat C P times (making a list of P Cs)
                              п       - collect up results in a list while...
                             S         - ...п condition: sum (while players have chips)
 µ                          µ          - ...п do: the monadic chain:
                         ¡             -   repeat...
                        ¤              -   ...¡ number of times: nilad and link(s) as a nilad:
                    ⁸                  -     chain's left argument (the chip list)
                     «3                -     minimum with three (vectorises)
                       Ḣ               -     head -- i.e. min(left-most player's chips, 3)
                   ?                   -   ...¡ action: if...
                  ¤                    -     ...? clause: nilad and link(s) as a nilad:
               Ø.                      -       the list [0,1]
                 X                     -       random choice (0 is falsey while 1 is truthy)
             $                         -     ...? then: last two links as a monad:
    ¦                                  -       sparsely apply...
   1                                   -       ...¦ to indices: one (the left-most)
  ’                                    -       ...¦ action: decrement (player lost a chip)
            ¦                          -       sparsely apply...
           ¤                           -       ...¦ to indices: nilad and link(s) as a nilad:
      .,2                              -         literal pair of literals .5 and two = [.5,2]
         Ż                             -         prepend a zero = [0,0.5,2]
          X                            -         random choice
                                       -         -- Note application to index .5 is a no-op
                                       -                 index 0 is the right-most entry (L) 
                                       -                 index 2 is the second entry (R) 
                          ṙ1           -   rotate the list left by one for the next п loop
                                     $ - last two links as a monad:
                                    $  -   last two links as a monad:
                                  J    -     range of length -- i.e. [1,2,3,...,turns+1]
                                   C   -     complement = 1-x        [0,-1,-2,...,-turns]
                                 "     -   zipped-appliction of:
                                ṙ      -     rotate left by
                                       -   -- i.e. rotate 1st left by 0, 2nd left by -1, ...)

Answer 5

C#, 356?+13? Bytes

Requires using System; for a total of +13 bytes to the code shown below, if I'm required to count that. Otherwise just plonk it in any class and call L(players, starting chips);.

static int i,j,k,l;public static void L(int p,int s){var r=new Random();var x=new int[p];for(i=0;i<p;i++)x[i]=s;
for(i=0;i<s*p;){for(j=0;j<p;j++){for(l=0;l<x[j]&l<3;l++){k=r.Next(-1,5);if(k<2){if(k==0){x[j]--;i++;}else{x[(p+j+k)%p]++;x[j]--;}}}Console.Write(a(x)+i);}}}public static string a(int[] x){var n="|";for(l=0;l<x.Length;)n+=x[l++]+" ";
return n;}

Sample output for a 2,2 game:

|1 3 0|2 2 0|1 3 0|1 3 0|0 4 0|0 3 1|0 3 1|2 1 1|1 2 1|1 2 1|0 3 1|0 3 1|0 3 1|1 1 2|1 1 2|1 1 2|0 2 2|1 1 2|0 1 3|1 0 3|0 1 3|0 1 3|0 1 3|1 0 3|1 0 3|1 0 3|0 1 3|1 0 3|0 1 3|0 0 4

Less golfed version:

using System;
//class omitted.
static int i,j,k,l;
public static void LCR(int pl, int sc){
var r=new Random();
var state = new int[pl];
for(i=0;i<pl;i++)state[i]=sc;
for(i=0;i<sc*pl;){
    for(j=0;j<pl;j++){
        for(l=0;l<state[j] && l<3;l++){
            k=r.Next(-1,5);
            if(k<2){
                if(k==0){state[j]--;i++;}else{state[(pl+j+k)%pl]++;state[j]--;}
            }
        }
        Console.Write(a(state)+i);
    }
}
}
public static string a(int[] x){
    var n="|";
    for(l=0;l<x.Length;)n+=x[l++]+" ";
    return n;
}

Answer 6

C# (Visual C# Interactive Compiler), 201 199 bytes

n=>m=>{var r=new Random();var j=Enumerable.Repeat(n,m).ToList();for(int i=0;j.Any(c=>c>0);i++,Print(j))for(int k=0,x=r.Next(6);k++<Math.Min(j[i%m],3);j[((x<1?-1:1)+i+m)%m]+=x<2?1:0,j[i%m]-=x<3?1:0);}

Try it online!

startingChips=>playerNum=>{
//Instantiate a new random number generator
var rng = new Random();
//Create a list of chips
var players = Enumerable.Repeat(startingChips, playerNum ).ToList();
//Loop as long any player still has chips
for(int turnNum = 0;players.Any(c=>c>0);
//And print the result every iteration
i++,Print(j))
//Get a random number within the range of 0-5 and loop for...
for(int k = 0,randomNum = rng.Next(6);
//either 3 or the amount of chips we have, whichever is smaller
k++<Math.Min(players[turnNum % playerNum ],3);
//Increment either the right player if the random number is 1, else increment the right player if it is 0
players[((randomNum<1?-1:1)+ turnNum + playerNum ) % playerNum ]+=x<2?1:0,
//Decrement current player if the die roll is under 3
players[ turnNum % playerNum ]-=x<3?1:0);}

Answer 7

Charcoal, 61 bytes

≔⁰ηＷΣθ«≔Ｅθ⭆⌊⟦κ׳⁼λη⟧‽⁶ιＵＭθ⁻⁺⁺κ№§ι⊕λ3№§ι⊖λ5ＬΦ§ιλ›μ2≔﹪⊕ηＬθη⟦⪫θ,

Try it online! Link is to verbose version of code. Alternates between outputting the dice rolls and chips left (neither the initial number of chips nor the number of chips in the centre are included in the output). Explanation:

≔⁰η

Start with the first player.

ＷΣθ«

Repeat until nobody has any chips left.

≔Ｅθ⭆⌊⟦κ׳⁼λη⟧‽⁶ι

Roll up to three dice for the current player. These dice are labelled 0-5, where 0-2 represent the dot, 3 is pass to left, 4 is to centre, 5 is to right.

ＵＭθ⁻⁺⁺κ№§ι⊕λ3№§ι⊖λ5ＬΦ§ιλ›μ2

Add the number of chips the player on the right passed left and the number of chips the player on the left passed right, but subtract the number of chips the player themselves passed on.

≔﹪⊕ηＬθη

Advance to the next player.

⟦⪫θ,

Output the the new numbers of chips held by the players.

It's actually simpler for everyone to roll their dice simultaneously, which can be done in 50 bytes, including printing the dice rolls as well as the chips left:

ＷΣθ«≔Ｅθ⭆⌊⟦κ³⟧‽⁶ιＵＭθ⁻⁺⁺κ№§ι⊕λ3№§ι⊖λ5ＬΦ§ιλ›μ2⟦⪫ι,⪫θ,

Try it online! Link is to verbose version of code.

Answer 8

05AB1E, 58 50 49 52 49 bytes

Version which outputs the same state when a turn player has 0 chips left (50 49 52 49 bytes):

и[=ÐO_#¾è3‚Ws\F5ÝΩ©3‹iε¾¹%NQ-}®≠iε®<¾+¹%NQ+}}}}D0›*¼

Try it online.

Version which skips players with 0 chips left (58 57 60 57 bytes):

и[=DO_#[D¾èDĀ#\¼}3‚Ws\F5ÝΩ©3‹iε¾¹%NQ-}®≠iε®<¾+¹%NQ+}}}}D0›*¼

Try it online.

The first input is the amount of players, second input the amount of chips per player.

Explanation (of the second version):

и                    # Create a list with a size of the (first) implicit input,
                     # filled with the second (implicit) input
[                    # Start an infinite loop:
 =                   #  Print the list with trailing newline, without popping the list
 DO_#                #  If the total amount of chips is 0: stop the infinite loop
 [                   #  Start an inner infinite loop:
  D¾è                #   Get the chips of the I'th player (I is 0 by default)
     D               #   Duplicate this
      Ā#             #   If it is NOT 0: stop the inner infinite loop
        \            #   Remove the duplicated chips for the next iteration
         ¼           #   And increase I by 1
 }                   #  After the inner infinite loop:
 3‚ß                 #  If the amount of chips is larger than 3: use 3 instead
    F                #  Loop that many times:
     5ÝΩ             #   Roll a random dice in the range [0,5]
     ©3‹i            #   If the dice-roll is 0, 1, or 2:
         ε¾¹%NQ-}    #    Remove a chip from the I'th player
         ®≠i         #    If the dice-roll is NOT 1:
            ε®<¾+    #     Go to the player left if 0; or right if 2
            ¹%NQ+}   #     And increase that player's chips by 1
    }}}              #  Close both if-statements and the loop
       Dd*           #  Make any negative amount of chips 0
          ¼          #  Increase I by 1