LeetCode第104题. 二叉树的最大深度

1.题目

尝试一下该题

2.解法

1.DFS

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */
int maxDepth(struct TreeNode* root) {
    if(!root)
        return 0;
    int max1 = maxDepth(root->left);
    int max2 = maxDepth(root->right);
    return max1 > max2 ? max1 + 1 : max2 + 1;
}

2.DFS

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */

void dfs(struct TreeNode *node,int depth,int *ans)
{
    if(!node)
        return;
    depth++;
    *ans = fmax(*ans,depth);
    dfs(node->left,depth,ans);
    dfs(node->right,depth,ans);
}
int maxDepth(struct TreeNode* root) {
    int ans=0;
    dfs(root, 0,&ans);
    return ans;
}