Several traversal algorithms of binary tree

<span style= "FONT-SIZE:14PX;" >/* two cross-tree traversal */#include <iostream> #include <cstring> #include <stack>using namespace Std;typedef    struct node{char data; struct node *lchild,*rchild;}    bintree;typedef struct node1{bintree *btnode; BOOL IsFirst;}    Btnode;void creatBinTree1 (bintree* &root)//Pre-sequence traversal create tree, shaped like a,b,c,#,#,d,#,#,e,#,#{char value;    cin>>value; if (value = = ' # ') root = NULL;        Recursive end condition Else {root = (Bintree *) malloc (sizeof (bintree));        Root->data = value;        CreatBinTree1 (Root->lchild);    CreatBinTree1 (Root->rchild);    }}void creatBinTree2 (char *s,bintree *&root)//Create a two-fork tree, s as a string {int I, shaped like a (b,c));    BOOL Isright=false;          stack<bintree*> S1;              Storage node stack<char> s2;    Store delimiter Bintree *p,*temp;    root->data=s[0];    root->lchild=null;    root->rchild=null;    S1.push (root);    I=1;           while (I<strlen (s)) {if (s[i]== ' (') { S2.push (S[i]);        Isright=false;        } else if (s[i]== ', ') {isright=true;            } else if (s[i]== ') ') {S1.pop ();        S2.pop ();            } else if (Isalpha (s[i))) {p= (Bintree *) malloc (sizeof (bintree));            p->data=s[i];            p->lchild=null;            p->rchild=null;            Temp=s1.top ();                if (isright==true) {temp->rchild=p;            cout<<temp->data<< "The right child is" <<s[i]<<endl;                } else {temp->lchild=p;            cout<<temp->data<< "The left child is" <<s[i]<<endl;        } if (s[i+1]== ' (') S1.push (p);    } i++;        }}void display (Bintree *root)//show tree structure {if (root!=null) {cout<<root->data;            if (root->lchild!=null) {cout<< ' ('; DiSplay (Root->lchild);            } if (root->rchild!=null) {cout<< ', ';            Display (root->rchild);        cout<< ') ';        }}}void PreOrder1 (Bintree *root)//recursive pre-order traversal {if (root!=null) {cout<<root->data<< "";        PreOrder1 (Root->lchild);    PreOrder1 (Root->rchild);        }}void inOrder1 (Bintree *root)//recursive middle order traversal {if (root!=null) {inOrder1 (root->lchild);        cout<<root->data<< "";    InOrder1 (Root->rchild);        }}void postOrder1 (Bintree *root)//recursive post-traversal {if (root!=null) {postOrder1 (root->lchild);        PostOrder1 (Root->rchild);    cout<<root->data<< "";    }}void PreOrder2 (Bintree *root)//non-recursive pre-order traversal {stack<bintree*> S;    Bintree *p=root; while (p!=null| |!            S.empty ()) {while (p!=null) {cout<<p->data<< "";            S.push (P);    p=p->lchild;    } if (!s.empty ()) {p=s.top ();            S.pop ();        p=p->rchild;    }}}void InOrder2 (Bintree *root)//non-recursive middle order traversal {stack<bintree*> S;    Bintree *p=root; while (p!=null| |!            S.empty ()) {while (p!=null) {s.push (P);        p=p->lchild;            } if (!s.empty ()) {p=s.top ();            cout<<p->data<< "";            S.pop ();        p=p->rchild;    }}}void PostOrder2 (Bintree *root)//Non-recursive post-traversal {stack<btnode*> s;    Bintree *p=root;    Btnode *temp; while (p!=null| |! S.empty ()) {while (p!=null)//Search down along Zuozi until a node with no left subtree is present {Btnode *btn= (Btnode *) ma            Lloc (sizeof (Btnode));            btn->btnode=p;            btn->isfirst=true;            S.push (BTN);        p=p->lchild;            } if (!s.empty ()) {temp=s.top ();            S.pop (); if (temp->isfirst==tRue)//Represents the first time it appears at the top of the stack {temp->isfirst=false;                S.push (temp);            p=temp->btnode->rchild; } else//second appears at the top of the stack {cout<<temp->btnode->data<& lt; "                ";            P=null;    }}}}void PostOrder3 (Bintree *root)//Non-recursive post-traversal {stack<bintree*> s;                      Bintree *cur;                 The current node Bintree *pre=null;    Node S.push (root) of the previous visit;        while (!s.empty ()) {cur=s.top ();           if ((cur->lchild==null&&cur->rchild==null) | | | (pre!=null&& (pre==cur->lchild| |  Pre==cur->rchild)) {cout<<cur->data<< "";            If the current node has no child nodes, or if the child has been visited S.pop ();        Pre=cur;            } else {if (cur->rchild!=null) S.push (cur->rchild); if (cur->lchild!=null) S.pusH (cur->lchild); }}}void postOrder4 (Bintree *root)//Non-recursive post-traversal {stack<bintree *> stack_tree; Bintree *t = root; Bintree *t_1 = null;while (T | |!stack_tree.empty ()) {while (t) {Stack_tree.push (t); t = T->lchild;} if (!stack_tree.empty ()) {t = Stack_tree.top (); if (t_1! = T && t->rchild) {//t_1 = = T, describes the element in the second access stack t_1 = T;t = T->rchild;} Else {cout<< "val =" <<stack_tree.top ()->data<<endl;stack_tree.pop (); t = NULL;}}}    int main (int argc, char *argv[]) {char s[100];        while (scanf ("%s", s) ==1) {Bintree *root= (Bintree *) malloc (sizeof (bintree));        CreatBinTree2 (S,root);        display (root);        cout<<endl;        PreOrder2 (root);        cout<<endl;        InOrder2 (root);        cout<<endl;        PostOrder2 (root);        cout<<endl;        PostOrder3 (root);    cout<<endl; } return 0;} </span>

Several traversal algorithms of binary tree