LeetCode—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.

给定一棵二叉树，求最浅深度。

只要计算左右子树最小深度+1即可，但要注意当没有左子树/右子树时，要计算另一个节点的深度，因为没有到达leaf节点。

class Solution {

public:

    int minDepth(TreeNode* root) {

        if(!root) return 0;

        if(!root->left) return 1+minDepth(root->right);

        if(!root->right) return 1+minDepth(root->left);

        return 1 + min(minDepth(root->left), minDepth(root->right));

    }

};