111.Minimum Depth of Binary Tree

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)); } };