二叉树的中序遍历:
/**
* Definition for a binary tree node.
* 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> ans;
find(ans,root);
return ans;
}
void find(vector<int> &ans,TreeNode *root) //迭代
{
stack<TreeNode*> rootTemp;
TreeNode *p=root;
while(p!=NULL||rootTemp.size()!=0)
{
if(p!=NULL)
{
rootTemp.push(p);
p=p->left;
}
else
{
p=rootTemp.top();
rootTemp.pop();
ans.push_back(p->val);
p=p->right;
}
}
}
/*
void find(vector<int> &ans, TreeNode *root) //递归
{
if(root==NULL)
return;
if(root->left)
find(ans,root->left);
ans.push_back(root->val);
if(root->right)
find(ans,root->right);
}
*/
};