fix: FastSim清牌效率优先 — 领牌出多牌+最小rank, 跟牌出最小压制

核心改动: 从'出最大的看谁能压'改为'出最省的清牌快'

领牌(新轮):
- 三张 > 对子 > 单张 (多牌优先)
- 始终用最小rank (保留大牌给跟牌阶段)

跟牌:
- 三张/对子: 找最小rank能压制的同类型
- 单张: 出最小的压制牌(保留大牌)

效果: 多牌29%→34% (+5%), 单张-4.4%, 0.7s/局
vs IsmctsBot: 34% vs 53%, 差距来自straight/飞机等复杂牌型在rollout中缺失

PdkFriendServer/Logic/SOIsmctsBot.cs

@@ -190,7 +190,9 @@ namespace PdkFriendServer.Logic
             return FastSim(o1g, o2g, mg, current, myGameNum, CardType1.DanZhang, myPos - 1, 0);
         }
 
-        // 快速模拟核心：全部用 byte[]。支持单张+对子。
+        // 快速模拟核心：清牌效率优先。
+        // 领牌：优先出多牌组合(3张>2张>1张)，用最小的 rank 保留大牌
+        // 跟牌：出最小的能压制的牌，保留大牌
         private bool FastSim(List<byte> h1, List<byte> h2, List<byte> my,
             int current, byte maxGameNum, CardType1 maxType, int maxPlayer, int depth)
         {
@@ -201,44 +203,63 @@ namespace PdkFriendServer.Logic
 
             var cur = current == 0 ? h1 : current == 1 ? h2 : my;
             bool isNewRound = maxPlayer == current || maxGameNum == 0;
+            bool isMe = (current == 2);
 
             if (isNewRound)
             {
                 if (cur.Count == 0) return false;
-                // 找对子（贪心：出最大的对子）
+
-                var groups = cur.GroupBy(g => g).Where(g => g.Count() >= 2).OrderByDescending(g => g.Key).ToList();
+                // 清牌效率排序: 三张 > 对子 > 单张。始终用最小的 rank
-                if (groups.Count > 0)
+                var groups = cur.GroupBy(g => g).OrderBy(g => g.Key).ToList();
+
+                // 三张（清 3 张）
+                var triples = groups.Where(g => g.Count() >= 3).ToList();
+                if (triples.Count > 0)
                 {
-                    var pair = groups[0];
+                    var t = triples[0];
-                    var toRemove = pair.Take(2).ToList();
+                    var toRemove = t.Take(3).ToList();
                     foreach (var g in toRemove) cur.Remove(g);
-                    return FastSim(h1, h2, my, (current + 1) % 3, pair.Key, CardType1.DuiZi, current, depth + 1);
+                    return FastSim(h1, h2, my, (current + 1) % 3, t.Key, CardType1.SanZhang, current, depth + 1);
                 }
-                // 单张
+
-                var sorted = cur.OrderByDescending(g => g).ToList();
+                // 对子（清 2 张）
-                byte play = sorted[0];
+                var pairs = groups.Where(g => g.Count() >= 2).ToList();
+                if (pairs.Count > 0)
+                {
+                    var p = pairs[0];
+                    var toRemove = p.Take(2).ToList();
+                    foreach (var g in toRemove) cur.Remove(g);
+                    return FastSim(h1, h2, my, (current + 1) % 3, p.Key, CardType1.DuiZi, current, depth + 1);
+                }
+
+                // 单张：出最小的
+                byte play = groups[0].Key;
                 cur.Remove(play);
                 return FastSim(h1, h2, my, (current + 1) % 3, play, CardType1.DanZhang, current, depth + 1);
             }
             else
             {
-                // 跟牌：找能压制的同类型牌
+                // 跟牌：有牌能压 → 出最小的压制牌
+                if (maxType == CardType1.DuiZi || maxType == CardType1.SanZhang)
+                {
+                    int need = maxType == CardType1.SanZhang ? 3 : 2;
+                    var groups = cur.GroupBy(g => g)
+                        .Where(g => g.Count() >= need && g.Key > maxGameNum)
+                        .OrderBy(g => g.Key).ToList();
+                    if (groups.Count > 0)
+                    {
+                        var g = groups[0];
+                        var toRemove = g.Take(need).ToList();
+                        foreach (var x in toRemove) cur.Remove(x);
+                        return FastSim(h1, h2, my, (current + 1) % 3, g.Key, maxType, current, depth + 1);
+                    }
+                }
+
+                // 单张跟牌：出最小的可压牌
                 var bigger = cur.Where(g => g > maxGameNum).OrderBy(g => g).ToList();
-                if (maxType == CardType1.DuiZi)
-                {
-                    // 对子：找 ≥2 张且大于 maxGameNum
-                    var pairGroups = cur.GroupBy(g => g).Where(g => g.Count() >= 2 && g.Key > maxGameNum).OrderBy(g => g.Key).ToList();
-                    if (pairGroups.Count > 0)
-                    {
-                        var pair = pairGroups[0];
-                        var toRemove = pair.Take(2).ToList();
-                        foreach (var g in toRemove) cur.Remove(g);
-                        return FastSim(h1, h2, my, (current + 1) % 3, pair.Key, CardType1.DuiZi, current, depth + 1);
-                    }
-                }
                 if (bigger.Count > 0)
                 {
-                    byte play = bigger[0];
+                    byte play = bigger[0]; // 最小压制
                     cur.Remove(play);
                     return FastSim(h1, h2, my, (current + 1) % 3, play, CardType1.DanZhang, current, depth + 1);
                 }