diff options
-rw-r--r-- | balanced_binary_tree.c | 27 | ||||
-rw-r--r-- | balanced_binary_tree.py | 34 |
2 files changed, 61 insertions, 0 deletions
diff --git a/balanced_binary_tree.c b/balanced_binary_tree.c new file mode 100644 index 0000000..c42ec00 --- /dev/null +++ b/balanced_binary_tree.c @@ -0,0 +1,27 @@ +// 110. Balanced Binary Tree +#include "leetcode.h" + +// given a binary tree, determine if it is height balanced + +int depth(struct TreeNode *root) { + if (!root) + return 0; + return fmax(depth(root->left), depth(root->right)) + 1; +} + +bool isBalanced(struct TreeNode *root) { + if (!root) + return true; + return isBalanced(root->left) && isBalanced(root->right) && + !(abs(depth(root->left) - depth(root->right)) > 1); +} + +int main() { + int r1i[] = {3, 9, 20, -1, -1, 15, 7}, r2i[] = {1, 2, 2, 3, 3, -1, -1, 4, 4}; + struct TreeNode *r1 = treenode_build(r1i, ARRAY_SIZE(r1i)); + struct TreeNode *r2 = treenode_build(r2i, ARRAY_SIZE(r2i)); + printf("%d\n", isBalanced(r1)); // expect: 1 + printf("%d\n", isBalanced(r2)); // expect: 0 + treenode_free(r1); + treenode_free(r2); +} diff --git a/balanced_binary_tree.py b/balanced_binary_tree.py new file mode 100644 index 0000000..a677b56 --- /dev/null +++ b/balanced_binary_tree.py @@ -0,0 +1,34 @@ +# 110. Balanced Binary Tree +import leetcode + +""" +given a binary tree, determine if it is height balanced +""" + + +class Solution(object): + def isBalanced(self, root): + """ + :type root: Optional[TreeNode] + :rtype: bool + """ + self.balanced = True + + def dfs(node): + if not node: + return 0 + l, r = dfs(node.left), dfs(node.right) + if abs(l - r) > 1: + self.balanced = False + return max(l, r) + 1 + + dfs(root) + return self.balanced + + +if __name__ == "__main__": + obj = Solution() + r1 = leetcode.treenode_build(vals=[3, 9, 20, None, None, 15, 7]) + r2 = leetcode.treenode_build(vals=[1, 2, 2, 3, 3, None, None, 4, 4]) + print(obj.isBalanced(r1)) + print(obj.isBalanced(r2)) |