An answer of http://nabetani.sakura.ne.jp/hena/ord18notfork/

yhpg.js

var _ = require('underscore');

function sum(ary) {
    'use strict';
    return _.reduce(ary, function(acc, e) {
        return _.isEmpty(e) ? acc + 0 : e === 'x' ? acc + 1 : acc + parseInt(e, 10);
    }, 0); 
}

function chooseCash(cash) {
    'use strict';
    return _.chain( _.zip(cash, [0, 1, 2, 3, 4]) )
    .sortBy(function(e) { return sum( e[0].split(',') ); })
    .map(function(e) { return e[1]; } ) 
    .first()
    .value();
}

function process(cash) {
    'use strict';
    var performance = [2, 7, 3, 5, 2], 
    index = 0,
    persons = 0;
    return _.map(_.zip(cash, [0, 1, 2, 3, 4]), function(e) {
        index = _.indexOf(_.toArray(e[0]), 'x');
        if(index === -1) {
            persons = sum( e[0].split(',') );
            persons -= _.min([persons, performance[e[1]]]);
            return persons.toString();
        } else {
            persons = sum( e[0].substr(0, index).split(',') );
            persons -= _.min([persons, performance[e[1]]]);
            return [persons, e[0].substr(index)].join();
        }
    });
}

function solve(src) {
    'use strict';
    var cash = ['0', '0', '0', '0', '0'],
    cashNo = 0;
    _.each(_.toArray(src), function(e) {
        if(e !== '.') {
            cashNo = chooseCash(cash);
            cash[cashNo] = [cash[cashNo], e].join();
        } else {
            cash = process(_.clone(cash));
        }
    });
    return _.map(cash, function(e) {
        return sum( e.split(',') );
    }).join();
}

module.exports = {
    solve: solve
};

yhpg_spec.js

var yhpg = require('./yhpg');
        
describe("yhpg.solve", function() {
    var inputs = [
        /*0*/ ['42873x.3.', '0,4,2,0,0'],
        /*1*/ ['1', '1,0,0,0,0'],
        /*2*/ ['.', '0,0,0,0,0'],
        /*3*/ ['x', '1,0,0,0,0'],    
        /*4*/ ['31.', '1,0,0,0,0'],
        /*5*/ ['3x.', '1,1,0,0,0'],    
        /*6*/ ['99569x', '9,9,6,6,9'],
        /*7*/ ['99569x33', '9,9,9,9,9'],
        /*8*/ ['99569x33.', '7,2,6,4,7'],    
        /*9*/ ['99569x33..', '5,0,4,0,5'],
        /*10*/ ['12345x3333.', '4,0,3,2,3'],
        /*11*/ ['54321x3333.', '3,0,3,0,4'],
        /*12*/ ['51423x3333.', '3,4,4,0,4'],
        /*13*/ ['12x34x.', '1,0,1,0,2'],
        /*14*/ ['987x654x.32', '7,6,4,10,5'],
        /*15*/ ['99999999999x99999999.......9.', '20,10,12,5,20'],
        /*16*/ ['997', '9,9,7,0,0'],
        /*17*/ ['.3.9', '1,9,0,0,0'],
        /*18*/ ['832.6', '6,6,0,0,0'],
        /*19*/ ['.5.568', '3,5,6,8,0'],
        /*20*/ ['475..48', '4,8,0,0,0'],
        /*21*/ ['7.2..469', '1,4,6,9,0'],    
        /*22*/ ['574x315.3', '3,3,1,7,1'],
        /*23*/ ['5.2893.x98', '10,9,5,4,1'],
        /*24*/ ['279.6xxx..4', '2,1,4,1,1'],
        /*25*/ ['1.1.39..93.x', '7,1,0,0,0'],
        /*26*/ ['7677749325927', '16,12,17,18,12'],
        /*27*/ ['x6235.87.56.9.', '7,2,0,0,0'],
        /*28*/ ['4.1168.6.197.6.', '0,0,3,0,0'],
        /*29*/ ['2.8.547.25..19.6', '6,2,0,0,0'],
        /*30*/ ['.5.3x82x32.1829..', '5,0,5,0,7'],
        /*31*/ ['x.1816..36.24.429.', '1,0,0,0,7'],
        /*32*/ ['79.2.6.81x..26x31.1', '1,0,2,1,1'],
        /*33*/ ['574296x6538984..5974', '14,13,10,15,14'],
        /*34*/ ['99.6244.4376636..72.6', '5,6,0,0,3'],
        /*35*/ ['1659.486x5637168278123', '17,16,16,18,17'],
        /*36*/ ['.5.17797.x626x5x9457.3.', '14,0,3,5,8'],
        /*37*/ ['..58624.85623..4.7..23.x', '1,1,0,0,0'],
        /*38*/ ['716.463.9.x.8..4.15.738x4', '7,3,5,8,1'],
        /*39*/ ['22xx.191.96469472.7232377.', '10,11,18,12,9'],
        /*40*/ ['24..4...343......4.41.6...2', '2,0,0,0,0'],
        /*41*/ ['32732.474x153.866..4x29.2573', '7,5,7,8,5'],
        /*42*/ ['786.1267x9937.17.15448.1x33.4', '4,4,8,4,10'],
        /*43*/ ['671714849.149.686852.178.895x3', '13,16,13,10,12'],
        /*44*/ ['86x.47.517..29621.61x937..xx935', '7,11,8,8,10'],
        /*45*/ ['.2233.78x.94.x59511.5.86x3.x714.', '4,6,10,8,8'],
        /*46*/ ['.793...218.687x415x13.1...x58576x', '8,11,8,6,9'],
        /*47*/ ['6.6x37.3x51x932.72x4x33.9363.x7761', '15,13,15,12,15'],
        /*48*/ ['6..4.x187..681.2x.2.713276.669x.252', '6,7,8,6,5'],
        /*49*/ ['.6.xx64..5146x897231.x.21265392x9775', '19,17,19,20,17'],
        /*50*/ ['334.85413.263314.x.6293921x3.6357647x', '14,14,12,16,10'],
        /*51*/ ['4.1..9..513.266..5999769852.2.38x79.x7', '12,10,13,6,10']
    ];

    for(var i = 0; i < inputs.length; ++i) {
        (function(src, expected) {
            it("should return " + expected + " (" + i + ").", function() {
                var actual = yhpg.solve(src);
                expect(actual).toBe(expected);
            });
        })(inputs[i][0], inputs[i][1]);
    }

});