思路1
class Solution {
public:
void flatten(TreeNode* root) {
while(root)
{
auto p=root->left;
if(p)//找到左儿子的右链
{
while(p->right) p=p->right;
//将右链插入
p->right=root->right;
root->right=root->left;
root->left=NULL;
}
//此时root已经没有左孩子,往右孩子遍历
root=root->right;
}
}
};
思路2
class Solution {
public:
TreeNode* pre=NULL;//记录遍历顺序的前继节点
void flatten(TreeNode* root) {//
if(!root) return;
if(pre)
{
pre->right=root;
pre->left=NULL;
}
pre=root;
auto r=root->right,l=root->left;
flatten(l);
flatten(r);
}
};
标签:pre,right,链表,114,二叉树,flatten,NULL,root,left
From: https://www.cnblogs.com/tangxibomb/p/17436385.html