Paste this into the browser console of https://devrel.wearedevelopers.com/code100-puzzles/041-hearts-and-minds/hearts-and-minds.html to see the result

riddle.js

const all = [...document.querySelectorAll("#canvas div")];

const map = {};

// I could use 4 filters but I rather loop once
all.forEach((a) => {
  const isBrain = a.textContent === "🧠";
  const isStraight = Number(a.classList[2].split("-")[1]) % 90 === 0
  const isLeft = Number(a.classList[0].split("-")[1]) < 50;

  const key = `${isBrain}${isStraight}${isLeft}`;

  map[key] = (map[key] ?? 0) + 1;
});

console.log({
  straightBrains: map["truetruetrue"] + map["truetruefalse"],
  leftBrains: map["truetruetrue"] + map["truefalsetrue"],
  straightHearts: map["falsetruetrue"] + map["falsetruefalse"],
  rightHearts: map["falsetruefalse"] + map["falsefalsefalse"],
});