day1.js

var numStrings = "1844 1123 1490 1478 1108 1120 1594 1101 1831 1146 1084 1535 1016 1722 1388 1188 1351 1477 1215 1678 1159 1558 1581 1400 1550 1306 1852 1745 1224 1896 1596 1005 1499 1797 976 1777 1129 1601 1058 1510 1704 1818 1795 1364 1276 1362 1801 1985 1421 1311 1855 1977 1613 1951 2001 1327 1872 1517 1040 1692 1595 1769 1956 1763 1470 1898 1366 1443 312 1685 1014 1409 1717 1105 1290 1703 1732 1939 1790 1164 1225 1474 1713 1413 1906 1488 1931 1702 1848 1668 1737 1614 1719 1647 1171 1508 1035 1133 1179 1180 1472 1414 1659 1820 1544 1697 1175 1033 1805 1576 1196 1597 1739 1291 1103 1457 1514 1462 1619 1683 1338 1604 1372 1653 16 1725 1181 1952 1201 1531 1505 1912 1527 1853 1905 1833 1913 1131 1069 1537 1754 1551 1435 1914 1093 1273 1726 1094 1439 1689 1607 1646 1588 1698 1539 1493 1352 1163 1482 1044 1523 1142 1253 1250 1986 1049 1330 1219 1162 1088 1100 1532 1727 1761 1107 1916 1220 1319 1098 1431 1260 1642 1269 1102 1432 1267 1824 1658 1149 1024 1963 1498 1904 1812 1600 1773 1283 1463 1776 1406";
var splitted = numStrings.split(" ");
var arr = [];
splitted.forEach(function (num) { return arr.push(parseFloat(num)); });
var twoSum = function (arr, target) {
    var numObject = {};
    arr.forEach(function (num, index) {
        var thisNum = num;
        numObject[thisNum] = index;
    });
    var resultant = [];
    arr.forEach(function (num, index) {
        var diff = target - num;
        if (numObject.hasOwnProperty(diff) && numObject[diff] !== index) {
            resultant.push(arr[index]);
        }
    });
    return resultant[0] * resultant[1];
};
twoSum(arr, 2020);
var threeSum = function (arr, sum) {
    // Fix the first element as A[i]
    for (var i = 0; i < arr.length - 2; i++) {
        // Fix the second element as A[j]
        for (var j = i + 1; j < arr.length - 1; j++) {
            // Now look for the third number
            for (var k = j + 1; k < arr.length; k++) {
                if (arr[i] + arr[j] + arr[k] == sum) {
                    console.log(arr[i], arr[j], arr[k]);
                    return arr[i] * arr[j] * arr[k];
                }
            }
        }
    }
};
threeSum(arr, 2020);