const solve = (str1, str2) => {
  if (str1.length !== str2.length) return false;

  const addToMap = (map, value) => {
    if (map.has(value)) {
      map.set(value, map.get(value) + 1)
    } else {
      map.set(value, 1);
    }
  };

  const removeToMap = (map, value) => {
    if(map.has(value)) {
      const count = map.get(value) - 1;
      if (count >= 0) {
        map.set(value, count);
        return true;
      }
    }
    return false;
  };

  const obj = {
    odd: new Map(),
    even: new Map()
  };
  for (let i = 0; i < str1.length; i++) {
    addToMap(i % 2 ? obj.even : obj.odd, str1[i]);
  }
  for (let i = 0; i < str2.length; i++) {
    if(!removeToMap(i % 2 ? obj.even : obj.odd, str2[i])) return false;
  }
  return true;
}

console.log(solve('abcd', 'cdab'));
console.log(solve('abcd', 'bcda'));