// For example you want to search for nested ul and ol in a DOM tree branch
// Give example <ol> <li> <ol> <li></li> </ol> </li> </ol> should retrun 2
function solution( tags = ['ul', 'ol']) {
const [uls, ols] = tags.map(tag => Array.from($(`${tag}`)));
const [logUl, logOl] = tags.map(tag => new Logger(`${tag}`));
deepSearch(uls, 'ul', logUl);
deepSearch(ols, 'ol', logOl);
return logUl.count + logOl.count;
}
class Logger { constructor(tag) { this.tag = tag; this.num = 0; } get count () { return this.num; } get tagName () { return this.tag; } countOne() { this.num++; } } function deepSearch(els = [], tag = "", log) { // if no such elements passed in if (!els.length) { return; } log.countOne(); // loop though the els and check whether contains tag els.forEach(el => { const targets = Array.from(el.getElementsByTagName(`${tag}`)); if (targets.length) { deepSearch(targets, tag, log); } }); }