​LeetCode 145​

class Solution {
public:
TreeNode* s[100005];
vector<int> ans;
int tag=0;
vector<int> postorderTraversal(TreeNode* root) {

if(root==NULL) return ans;
s[tag++]=root;
TreeNode* term;
while(tag>0)
{
term = s[tag-1];
if(term->left!=NULL&&term->left->val!=-999999)
{s[tag++]=term->left;continue;}

if(term->right!=NULL&&term->right->val!=-999999)
{s[tag++]=term->right;continue;}

if(s[tag-1]->val!=-999999)
ans.push_back(s[tag-1]->val);
(*s[tag-1]).val=-999999;
tag--;

}
return ans;

}
};

和上一题几乎一样