LeetCode之Minimum Depth of Binary Tree

 /*采用递归法求解。*/
class Solution {
public:
    int minDepth(TreeNode* root) {
        if(root == nullptr) return 0;
        if(root->left == nullptr && root->right == 0) return 1;
        if(root->left && !root->right) return 1 + minDepth(root->left);
        if(root->right && !root->left) return 1 + minDepth(root->right);
        if(root->left && root->right) return 1 + min(minDepth(root->left), minDepth(root->right));
    }
};