hello-algo/en/codes/javascript/chapter_tree/binary_tree_bfs.js

35 lines
1.1 KiB
JavaScript

/**
* File: binary_tree_bfs.js
* Created Time: 2022-12-04
* Author: IsChristina (christinaxia77@foxmail.com)
*/
const { arrToTree } = require('../modules/TreeNode');
const { printTree } = require('../modules/PrintUtil');
/* Level-order traversal */
function levelOrder(root) {
// Initialize queue, add root node
const queue = [root];
// Initialize a list to store the traversal sequence
const list = [];
while (queue.length) {
let node = queue.shift(); // Queue dequeues
list.push(node.val); // Save node value
if (node.left) queue.push(node.left); // Left child node enqueues
if (node.right) queue.push(node.right); // Right child node enqueues
}
return list;
}
/* Driver Code */
/* Initialize binary tree */
// Use a specific function to convert an array into a binary tree
const root = arrToTree([1, 2, 3, 4, 5, 6, 7]);
console.log('\nInitialize binary tree\n');
printTree(root);
/* Level-order traversal */
const list = levelOrder(root);
console.log('\nPrint sequence of nodes from level-order traversal = ' + list);