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.
二叉树的最小深度:
解法:
class Solution {
public:
int minDepth(TreeNode* root) {
if (root == NULL) return 0;
if (root->left == NULL && root->right == NULL) return 1;
if (root->left == NULL) return minDepth(root->right) + 1;
else if (root->right == NULL) return minDepth(root->left) + 1;
else return 1 + min(minDepth(root->left), minDepth(root->right));
}
};