Binary Tree Inorder Traversal
给一个二叉树, 做in order遍历.
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public List<Integer> inorderTraversal(TreeNode root) {
List<Integer> res = new ArrayList<Integer>();
Stack<TreeNode> st = new Stack<TreeNode>();
while(root != null || !st.isEmpty()){
while(root!=null){
st.push(root);
root = root.left;
}
root = st.pop();
res.add(root.val);
root = root.right;
}
return res;
}
}