226. 翻转二叉树
问题描述:
代码:
class Solution {
public TreeNode invertTree(TreeNode root) {
if(root==null)
return null;
Queue queue = new linkedList<>();
queue.offer(root);
while(!queue.isEmpty()){
TreeNode node = queue.poll();
TreeNode new1 = new TreeNode();
new1 = node.left;
node.left = node.right;
node.right =new1;
if(node.left!=null)
queue.offer(node.left);
if(node.right!=null)
queue.offer(node.right);
}
return root;
}
}
思路:
层序遍历
112. 路径总和
问题描述:
代码:
class Solution {
public boolean hasPathSum(TreeNode root, int targetSum) {
if(root==null)
return false;
Queue tree = new linkedList<>();
Queue val1 = new linkedList<>();
tree.offer(root);
val1.offer(root.val);
while(!tree.isEmpty()){
TreeNode a = tree.poll();
int t = val1.poll();
if(a.left==null&&a.right==null){
if(t==targetSum)
return true;
continue;
}
if(a.left!=null){
tree.offer(a.left);
val1.offer(a.left.val+t);
}
if(a.right!=null){
tree.offer(a.right);
val1.offer(a.right.val+t);
}
}
return false;
}
}
思路:
