//https://leetcode.com/problems/flatten-binary-tree-to-linked-list/
- 为什么这个解法可以ac,root都变了?????
//二叉树先序遍历变变变变变变变
public void flatten(TreeNode root) {
if (root == null) {
return;
}
flatten(root.left);
flatten(root.right);
TreeNode tmp = root.right;
root.right = root.left;
root.left = null;
while (root.right != null) {
root = root.right;
}
root.right = tmp;
}
- 为什么这个解法不能ac,明显是可以的????
// 这个为什么不能AC?????????
TreeNode res = new TreeNode(-1);
TreeNode tmp = res;
public void flatten2(TreeNode root) {
preO(root);
root = res.right;
}
public void preO(TreeNode root) {
tmp.right = new TreeNode(root.val);
tmp = tmp.right;
if (root.left != null) {
preO(root.left);
}
if (root.right != null) {
preO(root.right);
}
}
- 我心中的完美解法
public void flatten3(TreeNode root) {
if (root == null) {
return;
}
flatten3(root.left);
flatten3(root.right);
TreeNode right = root.right;
TreeNode tmp = root;
root.right = root.left;
root.left = null;
while (tmp.right != null) {
tmp = tmp.right;
}
tmp.right = right;
}
网友评论