diff --git "a/2101040022/chapter_7/\346\261\202\344\272\214\345\217\211\346\240\221\344\270\255\344\273\216\346\240\271\350\212\202\347\202\271\345\210\260\345\217\266\345\255\220\350\212\202\347\202\271.cpp" "b/2101040022/chapter_7/\346\261\202\344\272\214\345\217\211\346\240\221\344\270\255\344\273\216\346\240\271\350\212\202\347\202\271\345\210\260\345\217\266\345\255\220\350\212\202\347\202\271.cpp"
new file mode 100644
index 0000000000000000000000000000000000000000..2860a552a26122a2571ee8ac488de10192a736e4
--- /dev/null
+++ "b/2101040022/chapter_7/\346\261\202\344\272\214\345\217\211\346\240\221\344\270\255\344\273\216\346\240\271\350\212\202\347\202\271\345\210\260\345\217\266\345\255\220\350\212\202\347\202\271.cpp"
@@ -0,0 +1,240 @@
+#include<stdio.h>
+#include<malloc.h>
+#define MaxSize 100
+typedef char ElemType;
+typedef struct node
+{
+	ElemType data;
+	struct node *lchild;
+	struct node *rchild;
+}BTNode;
+void CreateBTree(BTNode *&b,char *str)
+{
+	BTNode *St[MaxSize],*p;
+	int top=-1,k,j=0;char ch;
+	b=NULL;
+	ch=str[j];
+	while(ch!='\0')
+	{
+		switch(ch)
+		{
+		case '(':top++;St[top]=p;k=1;break;
+		case ')':top--;break;
+		case ',':k=2;break;
+		default:p=(BTNode *)malloc(sizeof(BTNode));
+			p->data=ch;p->lchild=p->rchild=NULL;
+			if(b==NULL)
+				b=p;
+			else
+			{
+				switch(k)
+				{
+				case 1:St[top]->lchild=p;break;
+				case 2:St[top]->rchild=p;break;
+				}
+			}
+		}
+		j++;ch=str[j];
+	}
+}
+void DestroyBTree(BTNode *&b)
+{
+	if(b!=NULL)
+	{
+		DestroyBTree(b->lchild);
+		DestroyBTree(b->rchild);
+		free(b);
+	}
+}
+BTNode *FindNode(BTNode *b,ElemType x)
+{
+	BTNode *p;
+	if(b==NULL)
+		return NULL;
+	else if(b->data==x)
+		return b;
+	else
+	{
+		p=FindNode(b->lchild,x);
+		if(p!=NULL)
+			return p;
+		else
+			return FindNode(b->rchild,x);
+	}
+}
+BTNode *LchildNode(BTNode *p)
+{
+	return p->lchild;
+}
+BTNode *RchildNode(BTNode *p)
+{
+	return p->rchild;
+}
+int BTHeight(BTNode *b)
+{
+	int lchildh,rchildh;
+	if(b==NULL)return(0);
+	else
+	{
+		lchildh=BTHeight(b->lchild);
+		rchildh=BTHeight(b->rchild);
+		return (lchildh>rchildh)?(lchildh+1):(rchildh+1);
+	}
+}
+void DispBTree(BTNode *b)
+{
+	if(b!=NULL)
+	{
+		printf("%c",b->data);
+		if(b->lchild!=NULL||b->rchild!=NULL)
+		{
+			printf("(");
+			DispBTree(b->lchild);
+			if(b->rchild!=NULL)printf(",");
+			DispBTree(b->rchild);
+			printf(")");
+		}
+	}
+}
+
+
+
+void AllPath1(BTNode *b,ElemType path[],int pathlen)
+{
+	if(b!=NULL)
+	{
+		if(b->lchild==NULL&&b->rchild==NULL)
+		{
+			printf("%c到根结点逆路径：%c->",b->data,b->data);
+			for(int i=pathlen-1;i>0;i--)
+				printf("%c->",path[i]);
+			printf("%c\n",path[0]);
+		}
+		else
+		{
+			path[pathlen]=b->data;
+			pathlen++;
+			AllPath1(b->lchild,path,pathlen);
+			AllPath1(b->rchild,path,pathlen);
+		}
+	}
+}
+void LongPath1(BTNode *b,ElemType path[],int pathlen,ElemType longpath[],int &longpathlen)
+{
+	if(b==NULL)
+	{
+		if(pathlen>longpathlen)
+		{
+			for(int i=pathlen-1;i>=0;i--)
+				longpath[i]=path[i];
+			longpathlen=pathlen;
+		}
+	}
+	else
+	{
+		path[pathlen]=b->data;
+		pathlen++;
+		LongPath1(b->lchild,path,pathlen,longpath,longpathlen);
+		LongPath1(b->rchild,path,pathlen,longpath,longpathlen);
+	}
+}
+void AllPath2(BTNode *b)
+{
+	BTNode *st[MaxSize];
+	int top=-1;
+	BTNode *p,*r;
+	bool flag;
+	p=b;
+	do
+	{
+		while(p!=NULL)
+		{
+			top++;
+			st[top]=p;
+			p=p->lchild;
+		}
+		r=NULL;
+		flag=true;
+		while(top>=-1&&flag)
+		{
+			p=st[top];
+			if(p->rchild==r)
+			{
+				if(p->lchild==NULL&&p->rchild==NULL)
+				{
+					printf("%c到根结点逆路径：",p->data);
+					for(int i=top;i>0;i--)
+						printf("%c->",st[i]->data);
+					printf("%c\n",st[0]->data);
+				}
+				top--;
+				r=p;
+			}
+			else
+			{
+				p=p->rchild;
+				flag=false;
+			}
+		}
+	}while(top>-1);
+}
+void AllPath3(BTNode *b)
+{
+	struct snode
+	{
+		BTNode *node;
+		int parent;
+	}Qu[MaxSize];
+	int front,rear,p;
+	front=rear=-1;
+	rear++;
+	Qu[rear].node=b;
+	Qu[rear].parent=-1;
+	while(front<rear)
+	{
+		front++;
+		b=Qu[front].node;
+		if(b->lchild==NULL&&b->rchild==NULL)
+		{
+			printf("%c到根结点逆路径：",b->data);
+			p=front;
+			while(Qu[p].parent!=-1)
+			{
+				printf("%c->",Qu[p].node->data);
+				p=Qu[p].parent;
+			}
+			printf("%c\n",Qu[p].node->data);
+		}
+		if(b->lchild!=NULL)
+		{
+			rear++;
+			Qu[rear].node=b->lchild;
+			Qu[rear].parent=front;
+		}
+		if(b->rchild!=NULL)
+		{
+			rear++;
+			Qu[rear].node=b->rchild;
+			Qu[rear].parent=front;
+		}
+	}
+}
+int main()
+{
+	BTNode *b;
+	ElemType path[MaxSize],longpath[MaxSize];
+	int i,longpathlen=0;
+	CreateBTree(b,"A(B(D,E(H(J,K(L,M(,N))))),C(F,G(,I)))");
+	printf("二叉树b：");DispBTree(b);printf("\n");
+	printf("先序遍历方法：\n");AllPath1(b,path,0);
+	LongPath1(b,path,0,longpath,longpathlen);
+	printf("第一条最长逆路径长度：%d\n",longpathlen);
+	printf("第一条最长逆路径：");
+	for(i=longpathlen-1;i>=0;i--)
+		printf("%c",longpath[i]);
+	printf("\n");
+	printf("后序非递归遍历方法：\n");AllPath2(b);
+	printf("层次遍历方法：\n");AllPath3(b);
+	DestroyBTree(b);
+	return 1;
+}
\ No newline at end of file