力扣算犯学习day10-2

二叉树层序遍历相关–10道 7-8

116-填充每个节点的下一个右侧节点指针

题目

代码实现

/*
// Definition for a Node.
class Node {public int val;public Node left;public Node right;public Node next;public Node() {}public Node(int _val) {val = _val;}public Node(int _val, Node _left, Node _right, Node _next) {val = _val;left = _left;right = _right;next = _next;}
};
*/class Solution {public Node connect(Node root) {LinkedList<Node> queue = new LinkedList<>();if(root == null){return root;}queue.offer(root);while(!queue.isEmpty()){int len = queue.size();Node preNode = null;while(len > 0){Node node = queue.poll();if(preNode != null){preNode.next = node;}preNode = node;if(node.left != null){queue.offer(node.left);}if(node.right != null){queue.offer(node.right);}len--;}preNode.next = null;}return root;}
}

117-填充每个节点的下一个右侧节点指针II

题目

代码实现

/*
// Definition for a Node.
class Node {public int val;public Node left;public Node right;public Node next;public Node() {}public Node(int _val) {val = _val;}public Node(int _val, Node _left, Node _right, Node _next) {val = _val;left = _left;right = _right;next = _next;}
};
*/class Solution {public Node connect(Node root) {LinkedList<Node> queue = new LinkedList<>();if(root == null){return root;}queue.offer(root);while(!queue.isEmpty()){int len = queue.size();Node preNode = null;while(len > 0){Node node = queue.poll();if(preNode != null){preNode.next = node;}preNode = node;if(node.left != null){queue.offer(node.left);}if(node.right != null){queue.offer(node.right);}len--;}preNode.next = null;}return root;}
}