Given a binary tree, find its minimum depth.
The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.
C Solution 1:
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* struct TreeNode *left;
* struct TreeNode *right;
* };
*/
int minDepth(struct TreeNode* root) {
if (!root) return 0;
if (!root->left && !root->right) {
return 1;
}
int left = root->left ? minDepth(root->left) : INT_MAX;
int right = root->right ? minDepth(root->right) : INT_MAX;
return (left < right ? left : right) + 1;
}
C Solution 2:
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* struct TreeNode *left;
* struct TreeNode *right;
* };
*/
int minDepth(struct TreeNode* root) {
if (!root) return 0;
int left = minDepth(root->left);
int right = minDepth(root->right);
if (!left && !right) return 1;
if (left && right) return (left < right ? left : right) + 1;
return left + right + 1;
}
Summary:
- Try to avoid define another function.
LeetCode: 111. Minimum Depth of Binary Tree
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