From b7f030b1748affa4d36bfcb3c8dedca7ee0b653b Mon Sep 17 00:00:00 2001
From: yzyray <348533481@qq.com>
Date: Mon, 13 Sep 2021 10:46:50 +0800
Subject: [PATCH 1/2] Avoid use recursion

---
 .../featurecat/lizzie/rules/SGFParser.java    | 26 ++++++++-----------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/src/main/java/featurecat/lizzie/rules/SGFParser.java b/src/main/java/featurecat/lizzie/rules/SGFParser.java
index 3cc146e50..89a82e3e5 100644
--- a/src/main/java/featurecat/lizzie/rules/SGFParser.java
+++ b/src/main/java/featurecat/lizzie/rules/SGFParser.java
@@ -19,6 +19,7 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
+import java.util.Stack;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -652,8 +653,16 @@ private static void saveToStream(Board board, Writer writer) throws IOException
     // *  with 'xy' = coordinates ; or 'tt' for pass.
 
     // Write variation tree
-    builder.append(generateNode(board, history.getCurrentHistoryNode()));
-
+    Stack<BoardHistoryNode> stack = new Stack<>();
+    stack.push(history.getCurrentHistoryNode());
+    while (!stack.isEmpty()) {
+      BoardHistoryNode cur = stack.pop();
+      builder.append(generateNode(board, cur));
+      if (cur.numberOfChildren() >= 1) {
+        for (int i = cur.numberOfChildren() - 1; i >= 0; i--)
+          stack.push(cur.getVariations().get(i));
+      }
+    }
     // close file
     builder.append(')');
     writer.append(builder.toString());
@@ -698,19 +707,6 @@ private static String generateNode(Board board, BoardHistoryNode node) throws IO
           builder.append(String.format("LZ[%s]", formatNodeData(node)));
         }
       }
-
-      if (node.numberOfChildren() > 1) {
-        // Variation
-        for (BoardHistoryNode sub : node.getVariations()) {
-          builder.append("(");
-          builder.append(generateNode(board, sub));
-          builder.append(")");
-        }
-      } else if (node.numberOfChildren() == 1) {
-        builder.append(generateNode(board, node.next().orElse(null)));
-      } else {
-        return builder.toString();
-      }
     }
 
     return builder.toString();

From 2bb8f9e431681ee86cca4c0cd3178b6692a4a3bb Mon Sep 17 00:00:00 2001
From: yzyray <348533481@qq.com>
Date: Tue, 21 Sep 2021 11:07:31 +0800
Subject: [PATCH 2/2] Fix missing '(' and ')'

---
 .../java/featurecat/lizzie/rules/SGFParser.java  | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/main/java/featurecat/lizzie/rules/SGFParser.java b/src/main/java/featurecat/lizzie/rules/SGFParser.java
index 89a82e3e5..41070ccd7 100644
--- a/src/main/java/featurecat/lizzie/rules/SGFParser.java
+++ b/src/main/java/featurecat/lizzie/rules/SGFParser.java
@@ -653,14 +653,28 @@ private static void saveToStream(Board board, Writer writer) throws IOException
     // *  with 'xy' = coordinates ; or 'tt' for pass.
 
     // Write variation tree
+    BoardHistoryNode markerBeg = new BoardHistoryNode(null);
+    BoardHistoryNode markerEnd = new BoardHistoryNode(null);
     Stack<BoardHistoryNode> stack = new Stack<>();
     stack.push(history.getCurrentHistoryNode());
     while (!stack.isEmpty()) {
       BoardHistoryNode cur = stack.pop();
+      if (cur == markerBeg) {
+        builder.append('(');
+        continue;
+      }
+      if (cur == markerEnd) {
+        builder.append(')');
+        continue;
+      }
       builder.append(generateNode(board, cur));
+      boolean hasBrothers = (cur.numberOfChildren() > 1);
       if (cur.numberOfChildren() >= 1) {
-        for (int i = cur.numberOfChildren() - 1; i >= 0; i--)
+        for (int i = cur.numberOfChildren() - 1; i >= 0; i--) {
+          if (hasBrothers) stack.push(markerEnd);
           stack.push(cur.getVariations().get(i));
+          if (hasBrothers) stack.push(markerBeg);
+        }
       }
     }
     // close file