leetcode

Solution to some Leetcode problems written in C++

git clone git://git.dimitrijedobrota.com/leetcode.git

0543.cpp (921B)

0 class Solution { 1 public: 2 int diameterOfBinaryTree(TreeNode *root) { 3 unordered_map<TreeNode *, int> um; 4 stack<TreeNode *> st; 5 int res = 0; 6 7 while (root) { 8 st.push(root); 9 root = root->left; 10 } 11 12 while (!st.empty()) { 13 TreeNode *root = st.top(); 14 st.pop(); 15 if (um.find(root) == um.end()) { 16 um.insert({root, 1}); 17 st.push(root); 18 root = root->right; 19 while (root) { 20 st.push(root); 21 root = root->left; 22 } 23 } else { 24 if (!root->left && !root->right) continue; 25 int l = um[root->left]; 26 int r = um[root->right]; 27 res = max(l + r, res); 28 um[root] = 1 + max(l, r); 29 } 30 } 31 32 return res; 33 } 34 };