C++如何实现二叉树叶子节点个数计算

本文实例讲述了C++使用递归和非递归算法实现的二叉树叶子节点个数计算方法。分享给大家供大家参考，具体如下：

#include <stdlib.h>#include <iostream>#include <stack>using std::cout;using std::cin;using std::endl;using std::stack;typedef struct BTreeNode{  char elem;  struct BTreeNode *pleft;  struct BTreeNode *pright;}BTreeNode;int get_leaf_number(BTreeNode *proot){  if(proot == NULL)    return 0;  if(proot->pleft == NULL && proot->pright == NULL)    return 1;  return (get_leaf_number(proot->pleft) + get_leaf_number(proot->pright));}int preorder_get_leaf_number(BTreeNode* proot){  if(proot == NULL)    return 0;  int num = 0;  stack <BTreeNode*> st;  while (proot != NULL || !st.empty())  {    while (proot != NULL)    {      cout << "节点：" << proot->elem << endl;      st.push(proot);      proot = proot->pleft;    }    if (!st.empty())    {      proot = st.top();      st.pop();      if(proot->pleft == NULL && proot->pright == NULL)        num++;      proot = proot -> pright;    }  }  return num;}BTreeNode* btree_init(BTreeNode* &bt){  bt = NULL;  return bt;}void pre_crt_tree(BTreeNode* &bt){  char ch;  cin >> ch;  if (ch == '#')  {    bt = NULL;  }  else  {    bt = new BTreeNode;    bt->elem = ch;    pre_crt_tree(bt->pleft);    pre_crt_tree(bt->pright);  }}int main(){  int tree_leaf_number = 0;  BTreeNode *bt;  btree_init(bt);//初始化根节点  pre_crt_tree(bt);//创建二叉树  tree_leaf_number = get_leaf_number(bt);//递归  cout << "二叉树叶子节点个数为:" << tree_leaf_number << endl;  cout << "非递归先序遍历过程如下：" << endl;  tree_leaf_number = preorder_get_leaf_number(bt);//非递归  cout << "二叉树叶子节点个数为:" << tree_leaf_number << endl;  system("pause");  return 0;}