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authorcrupest <crupest@outlook.com>2020-10-02 18:52:07 +0800
committercrupest <crupest@outlook.com>2020-10-02 18:52:07 +0800
commit78e272d454c3cde15a48ca59e5825aaba1b2727d (patch)
treecaaa69aa06c2ef96b509f595dc54c0d30dc45a68 /works/solutions/cpp
parent9b8896185bda79c55f27d01ebf050f51dff90798 (diff)
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import(solutions): Add problem 865 .
Diffstat (limited to 'works/solutions/cpp')
-rw-r--r--works/solutions/cpp/865.cpp60
1 files changed, 60 insertions, 0 deletions
diff --git a/works/solutions/cpp/865.cpp b/works/solutions/cpp/865.cpp
new file mode 100644
index 0000000..8981a02
--- /dev/null
+++ b/works/solutions/cpp/865.cpp
@@ -0,0 +1,60 @@
+struct TreeNode
+{
+ int val;
+ TreeNode *left;
+ TreeNode *right;
+ TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+};
+
+#include <unordered_set>
+
+class Solution
+{
+public:
+ int max_depth = -1;
+ std::unordered_set<TreeNode *> deepest_nodes;
+
+ void record_depth(TreeNode *root, int depth)
+ {
+ if (depth > max_depth)
+ {
+ max_depth = depth;
+ deepest_nodes.clear();
+ }
+
+ if (depth == max_depth)
+ deepest_nodes.insert(root);
+
+ if (root->left != nullptr)
+ record_depth(root->left, depth + 1);
+ if (root->right != nullptr)
+ record_depth(root->right, depth + 1);
+ }
+
+ TreeNode *find_common_ancestor(TreeNode *root)
+ {
+ if (root == nullptr)
+ return nullptr;
+ if (deepest_nodes.find(root) != deepest_nodes.cend())
+ return root;
+
+ auto left = find_common_ancestor(root->left);
+ auto right = find_common_ancestor(root->right);
+
+ if (left != nullptr && right != nullptr)
+ return root;
+ if (left != nullptr)
+ return left;
+ if (right != nullptr)
+ return right;
+ return nullptr;
+ }
+
+ TreeNode *subtreeWithAllDeepest(TreeNode *root)
+ {
+ record_depth(root, 0);
+ return find_common_ancestor(root);
+ }
+};