diff --git a/NineChess/src/gamecontroller.cpp b/NineChess/src/gamecontroller.cpp
index 6a6b1fc7..c3ece74e 100644
--- a/NineChess/src/gamecontroller.cpp
+++ b/NineChess/src/gamecontroller.cpp
@@ -859,7 +859,7 @@ bool GameController::updateScence(NineChess &chess)
         int j;
 
         // 遍历棋盘，查找并放置棋盘上的棋子
-        for (j = NineChess::N_SEATS; j < (NineChess::N_SEATS) * (NineChess::N_RINGS + 1); j++) {
+        for (int j = NineChess::POS_BEGIN; j < NineChess::POS_END; j++) {
             if (board[j] == key) {
                 pos = scene.cp2pos(j / NineChess::N_SEATS, j % NineChess::N_SEATS + 1);
                 if (piece->pos() != pos) {
@@ -904,7 +904,7 @@ bool GameController::updateScence(NineChess &chess)
 
     // 添加开局禁子点
     if (chess.getRule()->hasForbiddenPoint && chess.getStage() == NineChess::GAME_PLACING) {
-        for (int j = NineChess::N_SEATS; j < (NineChess::N_SEATS) * (NineChess::N_RINGS + 1); j++) {
+        for (int j = NineChess::POS_BEGIN; j < NineChess::POS_END; j++) {
             if (board[j] == 0x0F) {
                 pos = scene.cp2pos(j / NineChess::N_SEATS, j % NineChess::N_SEATS + 1);
                 if (n < pieceList.size()) {
diff --git a/NineChess/src/ninechess.h b/NineChess/src/ninechess.h
index 8445b9d3..94efa3f9 100644
--- a/NineChess/src/ninechess.h
+++ b/NineChess/src/ninechess.h
@@ -31,9 +31,20 @@ public:
     // 8位，禁止修改！
     static const int N_SEATS = 8;
 
+    // 遍历棋盘点所用的起始位置，即 [8, 32)
+    static const int POS_BEGIN = N_SEATS;
+    static const int POS_END = ((N_RINGS + 1) * N_SEATS);
+
     // 预定义的规则数目
     static const int N_RULES = 4;
 
+    // 定义 move
+    typedef int move_t;
+
+    // 位置迭代器
+    // typedef typename std::vector<move_t>::iterator posIterator;
+    // typedef typename std::vector<move_t>::const_iterator constPosIterator;
+
     // 嵌套的规则结构体
     struct Rule
     {
diff --git a/NineChess/src/ninechessai_ab.cpp b/NineChess/src/ninechessai_ab.cpp
index f3d3ca3c..8a12ef62 100644
--- a/NineChess/src/ninechessai_ab.cpp
+++ b/NineChess/src/ninechessai_ab.cpp
@@ -53,7 +53,7 @@ void NineChessAi_ab::buildChildren(Node *node)
     case NineChess::ACTION_PLACE:
         // 对于开局落子
         if ((chessTemp.context.stage) & (NineChess::GAME_PLACING | NineChess::GAME_NOTSTARTED)) {
-            for (int i = NineChess::N_SEATS; i < (NineChess::N_RINGS + 1) * NineChess::N_SEATS; i++) {
+            for (int i = NineChess::POS_BEGIN; i < NineChess::POS_END; i++) {
                 if (!chessTemp.board_[i]) {
                     addNode(node, 0, i);
                 }
@@ -62,7 +62,7 @@ void NineChessAi_ab::buildChildren(Node *node)
         // 对于中局移子
         else {
             int newPos;
-            for (int oldPos = NineChess::N_SEATS; oldPos < (NineChess::N_RINGS + 1) * NineChess::N_SEATS; oldPos++) {
+            for (int oldPos = NineChess::POS_BEGIN; oldPos < NineChess::POS_END; oldPos++) {
                 if (!chessTemp.choose(oldPos))
                     continue;
                 if ((chessTemp.context.turn == NineChess::PLAYER1 &&
@@ -76,7 +76,7 @@ void NineChessAi_ab::buildChildren(Node *node)
                         }
                     }
                 } else {
-                    for (int j = NineChess::N_SEATS; j < (NineChess::N_RINGS + 1) * NineChess::N_SEATS; j++) {
+                    for (int j = NineChess::POS_BEGIN; j < NineChess::POS_END; j++) {
                         if (!chessTemp.board_[j]) {
                             addNode(node, 0, (oldPos << 8) + j);
                         }
@@ -89,13 +89,13 @@ void NineChessAi_ab::buildChildren(Node *node)
     case NineChess::ACTION_CAPTURE:
         // 全成三的情况
         if (chessTemp.isAllInMills(opponent)) {
-            for (int i = NineChess::N_SEATS; i < (NineChess::N_RINGS + 1) * NineChess::N_SEATS; i++) {
+            for (int i = NineChess::POS_BEGIN; i < NineChess::POS_END; i++) {
                 if (chessTemp.board_[i] & opponent) {
                     addNode(node, 0, -i);
                 }
             }
         } else if (!chessTemp.isAllInMills(opponent)) {
-            for (int i = NineChess::N_SEATS; i < (NineChess::N_RINGS + 1) * NineChess::N_SEATS; i++) {
+            for (int i = NineChess::POS_BEGIN; i < NineChess::POS_END; i++) {
                 if (chessTemp.board_[i] & opponent) {
                     if (!chessTemp.isInMills(i)) {
                         addNode(node, 0, -i);
diff --git a/NineChess/src/ninechessai_ab.h b/NineChess/src/ninechessai_ab.h
index c193b60c..4e5b8490 100644
--- a/NineChess/src/ninechessai_ab.h
+++ b/NineChess/src/ninechessai_ab.h
@@ -67,7 +67,7 @@ protected:
     void deleteTree(Node *node);
 
     // 增加新节点
-    void addNode(Node* parent, int value, int move);
+    void addNode(Node* parent, int value, NineChess::move_t move);
 
     // 评价函数
     int evaluate(Node *node);