leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
Log | Files | Refs | README | LICENSE

1008.cpp (680B)

      1 class Solution {
      2   public:
      3     TreeNode *bstFromPreorder(vector<int> &preorder) {
      4         int index = 0;
      5         TreeNode *root = new TreeNode(preorder[index++]);
      6         stack<TreeNode *> st;
      7         st.push(root);
      8         while (index < preorder.size()) {
      9             int val = preorder[index++];
     10             if (val < st.top()->val) {
     11                 st.push(st.top()->left = new TreeNode(val));
     12             } else {
     13                 TreeNode *crnt = nullptr;
     14                 while (!st.empty() && val > st.top()->val)
     15                     crnt = st.top(), st.pop();
     16                 st.push(crnt->right = new TreeNode(val));
     17             }
     18         }
     19         return root;
     20     }
     21 };