leetcode-question-counter.js

$(function() {

    let titleDOM = $('th.reactable-th-question_title').children('strong');
    let statusDOM = $('th.reactable-th-status');
    let tableDOM = $('tbody.reactable-data');
    let filtersDOM = $('div.filter-tag-bar');

    let refresh = function(){
        let count = $('tbody.reactable-data').children().length;
        let acCount = $('tbody.reactable-data').find('td[value="ac"]').length;
        titleDOM.text('Title' + ' (Total=' + count + ')');
        statusDOM.text(acCount);
    }

    refresh();

    let config = { attributes: true, childList: true, subtree: true };

    let observer = new MutationObserver(refresh);
    observer.observe(filtersDOM[0], config);
    
});