Leetcode:114. 二叉树展开为链表

题目:

给定一个二叉树，原地将它展开为链表。

例如，给定二叉树

    1
   / \
  2   5
 / \   \
3   4   6
将其展开为：

1
 \
  2
   \
    3
     \
      4
       \
        5
         \
          6

AC代码

void flatten(struct TreeNode* root){
    if(root != NULL){
        struct TreeNode* res = (struct TreeNode*)malloc(sizeof(struct TreeNode));
        res->val = -1;
        struct TreeNode* p1 = res;

        struct TreeNode* stack[10010];
        int index = -1;
        stack[++index] = root;
        while(index >= 0){
            struct TreeNode* temp = (struct TreeNode*)malloc(sizeof(struct TreeNode));
            temp = stack[index--];
            if(temp->right){
                stack[++index] = temp->right;
            }
            if(temp->left){
                stack[++index] = temp->left;
            }
            p1->left = NULL;
            p1->right = temp;
            p1 = p1->right;
        }
        p1->left = NULL;
        p1->right = NULL;
        root = res->right;
    }
}

 

来源：CSDN

作者：liuliuliudy

链接：https://blog.csdn.net/qq_33607393/article/details/104738424