【LeetCod】104. Maximum Depth of Binary Tree

Given a binary tree, find its maximum depth.

The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

Note: A leaf is a node with no children.

Example:

Given binary tree [3,9,20,null,null,15,7],

    3
   / \
  9  20
    /  \
   15   7

return its depth = 3.

解决办法：通过递归来计算树的深度

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */
int maxDepth(struct TreeNode *root) {
    typedef char ElemType;
    int lchilddep,rchilddep;
    if(root==NULL)
        return (0);//空树的深度为0
    else
    {
        lchilddep=maxDepth(root->left);
        rchilddep=maxDepth(root->right);
        return(lchilddep>rchilddep)?(lchilddep+1):(rchilddep+1);
    }
}