diff --git a/ex10/list.hpp b/ex10/list.hpp
index 0966c4a..c801595 100644
--- a/ex10/list.hpp
+++ b/ex10/list.hpp
@@ -109,7 +109,7 @@ template <class T>
 T List<T>::remove(listNode p)
 {
     if (!_size)
-        return NULL;
+        return 0;
 
     T temp = p->data;
     (p->pred)->succ = p->succ;
diff --git a/ex11/ex11.cpp b/ex11/ex11.cpp
index 9e07857..866eb7c 100644
--- a/ex11/ex11.cpp
+++ b/ex11/ex11.cpp
@@ -14,7 +14,7 @@ int main()
     std::string name;
     while (1)
     {
-        printf("选择操作:1添加/覆盖节点2添加边3删除节点4删除边5显示图\n");
+        printf("选择操作:1添加/覆盖节点2添加边3删除节点4删除边5显示图6广度优先遍历\n");
         scanf("%d", &op);
         switch (op)
         {
@@ -26,7 +26,7 @@ int main()
         case 2:
             printf("分别输入起始节点序号 到达节点序号 边权重:");
             std::cin >> id1 >> id2 >> w;
-            if(id1==id2)
+            if (id1 == id2)
                 printf("失败\n");
             switch (gv.link(id1, id2, w))
             {
@@ -64,6 +64,12 @@ int main()
             break;
         case 5:
             gv.display();
+            break;
+        case 6:
+            printf("输入起始节点序号:");
+            std::cin >> id1;
+            gv.BFS(id1);
+            break;
         default:
             break;
         }
diff --git a/ex11/graph.hpp b/ex11/graph.hpp
index 6066c9d..b29a173 100644
--- a/ex11/graph.hpp
+++ b/ex11/graph.hpp
@@ -1,11 +1,13 @@
 #ifndef _graph_hpp_
 #define _graph_hpp_
+#include "../ex10/queue.hpp"
 #include "vector.hpp"
 #include <iomanip>
 #include <iostream>
 #include <string>
-#include "../ex10/queue.hpp"
-
+#define DISCOVERED 1
+#define UNDISCOVERED 0
+#define VISITED 2
 
 template <class Te>
 class Edge
@@ -36,11 +38,13 @@ public:
     Tv data;
     int inDegree;
     int outDegree;
+    int status;
     Vertex()
     {
         // data = NULL;
         inDegree = 0;
         outDegree = 0;
+        status = UNDISCOVERED;
     }
     Vertex(Tv d)
     {
@@ -56,7 +60,7 @@ class graphVertex
 private:
     Vector<Vertex<Tv> *> V;
     Edge<Te> *E[100][100] = {NULL};
-    
+
     int v;
     int e;
 
@@ -101,7 +105,7 @@ public:
     }
     virtual Tv remove(int id)
     {
-        if(V[id]==NULL)
+        if (V[id] == NULL)
             return (Tv)0;
         for (int j = 0; j < v; j++)
         {
@@ -134,7 +138,7 @@ public:
         V[id2]->inDegree++;
         e++;
         Edge<Te> *temp = new Edge<Te>(w);
-        E[id1][id2]= temp;
+        E[id1][id2] = temp;
         return 0;
     }
     // 解除 id1->id2 连接
@@ -154,13 +158,14 @@ public:
         V[id2]->inDegree--;
 
         delete E[id1][id2];
+        E[id1][id2] = NULL;
         e--;
 
         return 0;
     }
 
     virtual void display()
-    {   
+    {
         // std::cout << std::setw(14) << temp->weight;
         //第一行
         std::cout << std::left << std::setw(14) << " ";
@@ -168,7 +173,7 @@ public:
             if (V[i] != NULL)
                 std::cout << std::setw(4) << i << std::setw(10) << V[i]->data;
         printf("\n");
-        
+
         for (int i = 0; i < V._len; i++)
             if (V[i] != NULL)
             {
@@ -183,7 +188,6 @@ public:
                             std::cout << std::setw(14) << E[i][j]->weight;
                         else
                             std::cout << std::setw(14) << "-";
-                            
                     }
                 printf("\n");
             }
@@ -191,22 +195,44 @@ public:
 
     virtual void BFS(int id)
     {
+        reset();
+        
+        if(V[id]==NULL)
+            return;
         Queue<int> q;
-
+        V[id]->status = DISCOVERED;
         q.enqueue(id);
         while (!q.empty())
         {
-           int vid = q.dequeue();
+            int vid = q.dequeue();
 
-           for (int j = 0; j < 100;j++)
-           {
-               if(E[id][j]!=NULL)
-                   q.enqueue(j);
-           }
+            for (int j = 0; j < 100; j++)
+            {
+                if (E[vid][j] != NULL)
+                {
+                    if (V[j]->status == UNDISCOVERED)
+                    {
+                        q.enqueue(j);
+                        V[j]->status = DISCOVERED;
+                        
+                    }
+                }
+            }
 
-           // std::cout << node->pos;
-           printf("ID: %d",q.dequeue());
+            // std::cout << node->pos;
+            printf("VISIT ID: %d \n", vid);
+            V[vid]->status = VISITED;
+        }
+    }
+    void reset()
+    {
+        for (int j = 0; j < V._len; j++)
+        {
+            if (V[j] != NULL)
+            {
 
+                V[j]->status = UNDISCOVERED;
+            }
         }
     }
 };