diff --git a/src/ai/movegen.cpp b/src/ai/movegen.cpp
index f4df48b3..c31c8c18 100644
--- a/src/ai/movegen.cpp
+++ b/src/ai/movegen.cpp
@@ -333,7 +333,7 @@ void MoveList::create()
 
 #ifdef DEBUG_MODE
     int sum = 0;
-    for (int i = 0; i < Board::N_LOCATIONS; i++) {
+    for (int i = 0; i < SQ_EXPANDED_COUNT; i++) {
         loggerDebug("/* %d */ {", i);
         for (int j = 0; j < DIRECTIONS_COUNT; j++) {
             if (j == DIRECTIONS_COUNT - 1)
diff --git a/src/ai/search.cpp b/src/ai/search.cpp
index c4370393..bfcf8895 100644
--- a/src/ai/search.cpp
+++ b/src/ai/search.cpp
@@ -201,19 +201,19 @@ struct AIAlgorithm::Node *AIAlgorithm::addNode(
     char cmd[32] = { 0 };
 
     if (move < 0) {
-        tempGame.position.board.squareToPolar(-move, r, s);
+        tempGame.position.board.squareToPolar(static_cast<square_t>(-move), r, s);
         sprintf(cmd, "-(%1u,%1u)", r, s);
     } else if (move & 0x7f00) {
         int r1, s1;
-        tempGame.position.board.squareToPolar(move >> 8, r1, s1);
-        tempGame.position.board.squareToPolar(move & 0x00ff, r, s);
+        tempGame.position.board.squareToPolar(static_cast<square_t>(move >> 8), r1, s1);
+        tempGame.position.board.squareToPolar(static_cast<square_t>(move & 0x00ff), r, s);
         sprintf(cmd, "(%1u,%1u)->(%1u,%1u)", r1, s1, r, s);
     } else {
-        tempGame.position.board.squareToPolar(move & 0x007f, r, s);
+        tempGame.position.board.squareToPolar(static_cast<square_t>(move & 0x007f), r, s);
         sprintf(cmd, "(%1u,%1u)", r, s);
     }
 
-    newNode->cmd = cmd;
+    strcpy(newNode->cmd, cmd);
 #endif // DEBUG_AB_TREE
 
     if (parent) {
diff --git a/src/ai/search.h b/src/ai/search.h
index 40e76fb8..b97a3d0d 100644
--- a/src/ai/search.h
+++ b/src/ai/search.h
@@ -76,7 +76,7 @@ public:
 
 #ifdef DEBUG_AB_TREE
         size_t id;                      // 结点编号
-        string cmd;
+        char cmd[32];
         int depth;                      // 深度
         bool evaluated;                 // 是否评估过局面
         int alpha;                      // 当前搜索结点走棋方搜索到的最好值，任何比它小的值对当前结点的走棋方都没有意义。当函数递归时 Alpha 和 Beta 不但取负数而且要交换位置