Cracking The Coding Interview4.5

//原文：////Write an algorithm to find the ‘next’ node (i.e., in-order successor) of a given node in a binary search tree where each node has a link to its parent.////译文：////给定二叉查找树的一个结点， 写一个算法查找它的“下一个”结点(即中序遍历后它的后继结点)， 其中每个结点都有指向其父亲的链接。//  下个节点为父节点或者右子树的最左叶子#include <iostream>#include <string>#include <queue>#include <stack>#include <list>using namespace std;struct treenode{char data;treenode * left;treenode * right;treenode * parent;};class tree{public:tree(){//root = create();root = NULL;index = 0;}~tree(){/***清空二叉树***/}/***二叉排序树：插入。***/void insert(char *s){if (s == NULL){return;}int size = strlen(s);for (int i = 0; i<size; i++){insert(&root, s[i], NULL);}}void levelOrder(){queue<treenode *> q;if (root != NULL){q.push(root);}while(!q.empty()){treenode *t = q.front();cout<<t->data<<endl;q.pop();if (t->left != NULL){q.push(t->left);}if (t->right != NULL){q.push(t->right);}}}treenode * findNext(treenode *p){if (p->right == NULL){return p->parent;} else{treenode *s = p->right;while(s->left != NULL){s = s->left;}return s;}}void preOrder(){pOrder(root);}void inOreder(){zOrder(root);}void postOreder(){  hOrder(root);}treenode *root;private:int index;void insert(treenode **p, char s, treenode *parent){if (((*p) == NULL) && s != '\0'){*p = new treenode;(*p)->data = s;(*p)->left = NULL;(*p)->right = NULL;(*p)->parent = parent;} else{if ((*p)->data > s){insert(&((*p)->left) , s, *p);} else{insert(&((*p)->right) , s, *p);}}}void pOrder(treenode *p){if (p==NULL){return;}cout<<p->data<<"  "<<endl;pOrder(p->left);pOrder(p->right);}void zOrder(treenode *p){if (p==NULL){return;}zOrder(p->left);cout<<p->data<<"  "<<endl;zOrder(p->right);}void hOrder(treenode *p){if (p==NULL){return;}hOrder(p->left);cout<<p->data<<"  "<<endl;hOrder(p->right);}};int main(){/**非递归层次遍历*************************/tree s;char t[8] = "3289654";s.insert(t);//s.levelOrder();treenode *p =s.findNext((s.root)->right);cout<<p->data<<endl;return 0;}