04. Table

function solve() {
  const tr = document.getElementsByTagName('tr');
  let lastClicked;

  [...tr].forEach((row) => {
    row.addEventListener('click', (event) => {
      const element = event.target.parentNode.style;

      if (!element.backgroundColor) {

        element.backgroundColor = '#413f5e';

        if (lastClicked) {
          lastClicked.backgroundColor = '';
        }

      } else {
        element.backgroundColor = '';
      }

      lastClicked = element;
    });
  });
}