salamtamp

const isSwapOneTime = (input) => {
  const diff = (a, b) => a.filter((i, idx) => i !== b[idx]);
  const sort = (a) => [ ...a ].sort();
  const sorted = sort(input);
  return diff(input, sorted).length <= 2;
}

console.log(isSwapOneTime([1, 2, 4, 5, 3])); //false
console.log(isSwapOneTime([1, 3, 3, 4, 5])); //true
console.log(isSwapOneTime([1, 2, 3, 4, 5])); //true

salamtamp

function bingap(n) {
  const binary = (n >>> 0).toString(2);
  const f1 = new RegExp(/1?0+1?/, 'g');
  const f2 = new RegExp(/1(0+)1/);
  return binary.match(f1)
               .filter(r1 => r1.match(f2))
               .reduce((acc, n) => acc > n.length - 2 ? acc : n.length - 2, 0)
}

console.log(bingap(42));

salamtamp

// Use Gists to store code you would like to remember later on
console.log(window); // log the "window" object to the console