LeetCode 199. 二叉树的右视图

 1 /**
 2  * Definition for a binary tree node.
 3  * struct TreeNode {
 4  *     int val;
 5  *     struct TreeNode *left;
 6  *     struct TreeNode *right;
 7  * };
 8  */
 9 
10 
11 /**
12  * Note: The returned array must be malloced, assume caller calls free().
13  */
14 
15  void pre(struct TreeNode* root, int* returnSize,int depth,int* result)
16  {
17      if(root==NULL){
18          return ;
19      }
20      if(depth+1>*returnSize){
21          *returnSize=depth+1;
22      }
23      result[depth]=root->val;
24      pre(root->left,returnSize,depth+1,result);
25      pre(root->right,returnSize,depth+1,result);
26  }
27 int* rightSideView(struct TreeNode* root, int* returnSize){
28     *returnSize=0;
29     int* result;
30     result=(int*)malloc(1000*sizeof(int));
31     pre(root,returnSize,0,result);
32     return result;
33 }