Given a binary tree, return the inorder traversal of its nodes‘ values.
For example:
Given binary tree {1,#,2,3},
   1
         2
    /
   3
return [1,3,2].
Note: Recursive solution is trivial, could you do it iteratively?
confused what "{1,#,2,3}" means? >
 read more on how binary tree is serialized on OJ.
用非递归的方法实现二叉树的中序遍历。
/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    vector<int> inorderTraversal(TreeNode *root) {
        vector<int>result;
        stack<TreeNode*>st;
        TreeNode*node=root;
        //左孩子不断入栈
        while(node){st.push(node); node=node->left;}
        while(!st.empty()){
            //访问栈顶元素
            node=st.top(); st.pop();
            result.push_back(node->val);
            node=node->right;
            //右子树的左孩子不断入栈
            while(node){st.push(node); node=node->left;}
        }
        return result;
    }
};LeetCode: Binary Tree Inorder Traversal [094],布布扣,bubuko.com
LeetCode: Binary Tree Inorder Traversal [094]
原文地址:http://blog.csdn.net/harryhuang1990/article/details/27958187