hello-algo/codes/javascript/include/PrintUtil.js

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2022-12-04 15:14:09 +00:00
/**
* File: PrintUtil.js
* Created Time: 2022-12-04
* Author: IsChristina (christinaxia77@foxmail.com)
*/
function Trunk(prev, str) {
this.prev = prev;
this.str = str;
}
/**
* Print a linked list
* @param head
*/
function printLinkedList(head) {
let list = [];
while (head !== null) {
list.push(head.val.toString());
head = head.next;
}
console.log(list.join(" -> "));
}
/**
* The interface of the tree printer
* This tree printer is borrowed from TECHIE DELIGHT
* https://www.techiedelight.com/c-program-print-binary-tree/
* @param root
*/
function printTree(root) {
printTree(root, null, false);
}
/**
* Print a binary tree
* @param root
* @param prev
* @param isLeft
*/
function printTree(root, prev, isLeft) {
if (root === null) {
return;
}
let prev_str = " ";
let trunk = new Trunk(prev, prev_str);
printTree(root.right, trunk, true);
if (!prev) {
trunk.str = "———";
} else if (isLeft) {
trunk.str = "/———";
prev_str = " |";
} else {
trunk.str = "\\———";
prev.str = prev_str;
}
showTrunks(trunk);
console.log(" " + root.val);
if (prev) {
prev.str = prev_str;
}
trunk.str = " |";
printTree(root.left, trunk, false);
}
/**
* Helper function to print branches of the binary tree
* @param p
*/
function showTrunks(p) {
if (!p) {
return;
}
showTrunks(p.prev);
console.log(p.str);
}
module.exports = {
printTree,
printLinkedList,
}