ReportRepairOneTwo.java

import java.util.HashSet;
import java.util.Set;

public class ReportRepairOneTwo {
  public static void main(String args[]) {
    int[] list = { 1837, 1585, 1894, 1715, 1947, 1603, 1746, 1911, 1939, 1791, 1800, 1479, 1138, 1810, 1931, 1833, 1470,
        1882, 1725, 1496, 1890, 1862, 1990, 1958, 1997, 1844, 1524, 541, 2001, 1591, 1687, 1941, 1940, 1561, 1813, 1654,
        1500, 1575, 1826, 2006, 679, 1660, 1679, 1631, 2008, 575, 1583, 1883, 1904, 1436, 1650, 1532, 1907, 1803, 1693,
        1700, 359, 1516, 1625, 1908, 1994, 1910, 1644, 1706, 1781, 1639, 1662, 1712, 1796, 1915, 1550, 1721, 1697, 1917,
        1665, 1646, 1968, 1881, 1893, 1468, 1678, 1774, 285, 1754, 1856, 1677, 1823, 1802, 1681, 1587, 1767, 1711, 1900,
        1983, 1787, 1996, 1726, 1982, 1971, 1553, 1542, 1863, 2002, 1831, 1891, 1555, 2000, 1847, 1783, 1873, 1761,
        1742, 1534, 1993, 1898, 1973, 1974, 1597, 1540, 1581, 1864, 1452, 1637, 1649, 1886, 1965, 1460, 1664, 1701,
        1647, 1812, 1937, 1902, 2004, 1991, 1718, 1887, 1606, 1748, 1737, 1608, 1641, 1710, 1724, 705, 1985, 1571, 1805,
        131, 1788, 1707, 1513, 1615, 1897, 1476, 1927, 1745, 1926, 1839, 1807, 1955, 1692, 1645, 1699, 1471, 1604, 1830,
        1622, 1972, 1866, 1814, 1816, 1855, 1820, 1034, 1673, 1704, 1969, 1580, 1980, 1739, 1896, 434, 497, 1851, 1933,
        458, 1521, 1551, 1762, 2010, 1614, 1840, 1747, 1875, 1836, 1895, 1518, 1825, 1987 };

    Set<Integer> set = new HashSet<>();

    for (int idx = 0; idx < list.length; idx++) {
      int sumComplement = 2020 - list[idx];

      for (Integer i : set) {
        int secondComplement = sumComplement - i;
        if (set.contains(secondComplement)) {
          System.out.println(list[idx]);
          System.out.println(secondComplement);
          System.out.println(i);
          System.out.println(list[idx] * secondComplement * i);
          return;
        }
      }

      set.add(list[idx]);

    }
  }
}