Reverse Groups

Reverse Groups

var fs = require("fs");
fs.readFileSync(process.argv[2]).toString().split('\n').forEach(function (line) {
    if (line != "") {
        var parsedLine = line.split(";");
        var k = parsedLine[1];
        var digits = parsedLine[0].split(",");
        var length = digits.length;
        if (k > 1) {
            for (var i = 1; i <= length; i++) {
                if (i % (k) === 0) {
                    var upper = i - 1;
                    var lower = i - k;
                    var tmp;
                    while (upper > lower) {
                        tmp=digits[upper];
                        digits[upper]=digits[lower];
                        digits[lower]=tmp;
                        upper--;
                        lower++;
                    }
                }
            }
        }
        console.log(digits.join());
    }
});