66_leetcode_Binary Tree Inorder Traversal

Given a binary tree, return the inorder traversal
of its nodes' values.(采用非递归的方法）

1:设置堆栈； 2:访问顺序，左子树，根节点，右子树。

vector<int> inorderTraversal(TreeNode *root)
{
vector<int> result;
if(root == NULL)
{
return result;
}

stack<TreeNode* > myStack;

TreeNode* curNode = root;
while(curNode || !myStack.empty())
{
while(curNode)
{
myStack.push(curNode);
curNode = curNode->left;
}

curNode = myStack.top();
result.push_back(curNode->val);
curNode = curNode->right;
myStack.pop();
}
return result;
}