題目描述:
給定一個二叉樹,原地將它展開爲一個單鏈表。
例如,給定二叉樹
1
/ \
2 5
/ \ \
3 4 6
將其展開爲:
1
\
2
\
3
\
4
\
5
\
6
代碼:
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
void flatten(TreeNode* root) {
while(root)
{
if(root->left)
{
TreeNode *temp_root=root->left;
while(temp_root->right)
{
temp_root=temp_root->right;
}
temp_root->right=root->right;
root->right=root->left;
root->left=NULL;
}
root=root->right;
}
}
};