private static TreeNode GetTree(int val, TreeNode temp1, TreeNode temp2)
{
TreeNode root = new LeetCode.TreeNode(val);
root.left = temp1;
root.right = temp2;
return(root);
}
public TreeProblems()
{
LeetCode.TreeNode node = root;
node.left = new LeetCode.TreeNode(2);
node.right = new LeetCode.TreeNode(2);
node = root.right;
node.left = new LeetCode.TreeNode(4);
node.right = new LeetCode.TreeNode(3);
node = root.left;
node.left = new LeetCode.TreeNode(4);
node.right = new LeetCode.TreeNode(3);
node = root.left.right;
node.left = new LeetCode.TreeNode(8);
node.right = new LeetCode.TreeNode(9);
node = root.right.right;
node.left = new LeetCode.TreeNode(8);
node.right = new LeetCode.TreeNode(9);
}
/// <summary>
/// 给定一棵树，原地展开它，使用右子树作为链表；先序遍历展开
/// </summary>
/// <param name="root"></param>
public void Flatten(TreeNode root)
{
while (root != null)
{
if (root.left != null)
{
TreeNode leftTmp = root.left;
TreeNode leftRight = leftTmp;
while (leftRight.right != null)
{
leftRight = leftRight.right;
}
root.left = null;
leftRight.right = root.right;
root.right = leftTmp;
}
root = root.right;
}
}
private TreeNode ConstructMaximumBinaryTree(int[] nums, int lo, int hi)
{
if (lo > hi)
{
return(null);
}
int maxIndex = lo;
for (int i = lo + 1; i <= hi; i++)
{
if (nums[i] > nums[maxIndex])
{
maxIndex = i;
}
}
TreeNode root = new LeetCode.TreeNode(nums[maxIndex]);
root.left = ConstructMaximumBinaryTree(nums, lo, maxIndex - 1);
root.right = ConstructMaximumBinaryTree(nums, maxIndex + 1, hi);
return(root);
}
