From 63df46eee68edd380386792381bebc4ba4cf0429 Mon Sep 17 00:00:00 2001
From: Joseph Montanaro <jfmontanaro@modg.org>
Date: Fri, 5 Nov 2021 10:27:09 -0700
Subject: [PATCH] reuse dice for subsequent legs in randomGame

---
 .gitignore      |  3 ++-
 combinators.nim |  9 +--------
 simulation.nim  | 12 +++++++++---
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/.gitignore b/.gitignore
index 4d8d0fc..1756b4b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 *.exe
-profile_results.txt
\ No newline at end of file
+profile_results.txt
+callgrind.out.*
\ No newline at end of file
diff --git a/combinators.nim b/combinators.nim
index 903d1a7..57d9233 100644
--- a/combinators.nim
+++ b/combinators.nim
@@ -1,4 +1,4 @@
-import algorithm, random, sugar
+import algorithm
 import fixedseq, game
 
 
@@ -87,10 +87,3 @@ iterator possibleFutures*(dice: FixedSeq): auto =
       for i in 0 .. dice.high:
         f.add((perm[i], digits[i]))
       yield f
-
-
-proc randomFuture*(dice: FixedSeq, r: var Rand): FixedSeq[5, Die, int8] =
-  result.initFixedSeq
-  let order = dice.dup(shuffle(r))
-  for i, color in order:
-    result.add((color, r.rand(1..3)))
diff --git a/simulation.nim b/simulation.nim
index 38b4da6..425d718 100644
--- a/simulation.nim
+++ b/simulation.nim
@@ -69,12 +69,18 @@ proc getLegScores*(b: Board): ScoreSet =
 
 proc randomGame*(b: Board, r: var Rand): Color =
   var projection = b
+  var dice = projection.diceRemaining
+
   while true:
-    for roll in randomFuture(projection.diceRemaining, r):
-      projection.advance(roll)
+    dice.shuffle(r)
+    for color in dice:
+      projection.advance((color, r.rand(1..3)))
       if projection.gameOver:
         return projection.winner.get
-    projection.resetDice()
+    # if we started with <5 dice, we need to reset for the next full leg
+    if dice.len < 5:
+      projection.resetDice()
+      dice = projection.diceRemaining
 
 
 proc randomGamesWorker(b: Board, count: Natural, r: var Rand): ScoreSet =