luke9.js

console.time('luke9');
loop1:
for (var i = 203; i < 498; i++) {
  for (var j = 987; j > 501; j--) {
    if (('' + i + j + (i+j)).split('').sort().join('') === '0123456789') {
      console.log(Math.min(i, j))
      break loop1
    }
  }
}
console.timeEnd('luke9');