An answer of http://nabetani.sakura.ne.jp/hena/ordf09rotbox/

yhpg.cpp

#include <vector>
#include <string>
#include <sstream>
#include <iostream>
#include <algorithm>

using  matrix_t = std::vector<std::vector<int>>;

const std::string commands { "abcdefihglkj" };

matrix_t transpose(const matrix_t matrix)
{
    auto m = matrix;
    for(std::size_t i = 0; i < matrix.size(); ++i) {
        for(std::size_t j = 0; j < matrix[i].size(); ++j) {
            m[i][j] = matrix[j][i];
        }
    }
    return m;
}

matrix_t shift(const matrix_t & matrix, char cmd)
{
    auto m = matrix;
    const auto p = commands.find(cmd) % matrix.size();
    std::rotate(m[p].begin(), m[p].begin() + 1, m[p].end());
    return m;
}

std::string format(const matrix_t & matrix)
{
    std::stringstream ss;
    for(std::size_t i = 0; i < matrix.size(); ++i) {
        for(auto && e : matrix[i]) {
            ss << e;
        }
        if(i + 1 < matrix.size()) {
            ss << "/";
        }
    }
    return ss.str();
}

std::string solve(const std::string & src)
{
    matrix_t matrix = {
        { 1, 2, 3 },
        { 4, 5, 6 },
        { 7, 8, 9 },
    };

    for(auto && chr : src) {
        if('a' <= chr && chr <= 'c') {
            matrix = shift(matrix, chr);
        } else if('d' <= chr && chr <= 'f') {
            auto m = transpose(matrix);
            m = shift(shift(m, chr), chr);
            matrix = transpose(m);
        } else if('g' <= chr && chr <= 'i') {
            matrix = shift(shift(matrix, chr), chr);
        } else {
            auto m = transpose(matrix);
            m = shift(m, chr);
            matrix = transpose(m);
        }
    }

    return format(matrix);
}

void test(const std::string & src, const std::string & expected)
{
    const auto actual = solve(src);
    if(actual != expected) {
        std::cout << "FAILED: [src=" << src << "]" << " [actual=" << actual << "]" << " [expected=" << expected << "]" << std::endl;
    }
}

void test_all()
{
    /*0*/ test("aegj", "286/435/971");
    /*1*/ test("a", "231/456/789");
    /*2*/ test("e", "183/426/759");
    /*3*/ test("g", "123/456/978");
    /*4*/ test("j", "126/459/783");
    /*5*/ test("bb", "123/645/789");
    /*6*/ test("jjj", "123/456/789");
    /*7*/ test("bd", "723/164/589");
    /*8*/ test("ah", "231/645/789");
    /*9*/ test("bj", "124/569/783");
    /*10*/ test("db", "723/561/489");
    /*11*/ test("dh", "723/615/489");
    /*12*/ test("dl", "123/456/789");
    /*13*/ test("hc", "123/645/897");
    /*14*/ test("gf", "128/453/976");
    /*15*/ test("hl", "623/745/189");
    /*16*/ test("ja", "261/459/783");
    /*17*/ test("ld", "123/456/789");
    /*18*/ test("ki", "315/486/729");
    /*19*/ test("lfa", "294/753/186");
    /*20*/ test("kga", "531/486/972");
    /*21*/ test("dbi", "372/561/489");
    /*22*/ test("che", "193/625/847");
    /*23*/ test("iea", "823/416/759");
    /*24*/ test("gbl", "523/964/178");
    /*25*/ test("egj", "186/425/973");
    /*26*/ test("jcf", "127/456/839");
    /*27*/ test("djh", "726/915/483");
    /*28*/ test("hld", "123/645/789");
    /*29*/ test("leeh", "453/678/129");
    /*30*/ test("heja", "851/629/743");
    /*31*/ test("cakh", "251/649/837");
    /*32*/ test("bhjik", "652/489/713");
    /*33*/ test("eabji", "483/269/751");
    /*34*/ test("cdbch", "823/156/974");
    /*35*/ test("ckgajc", "536/492/817");
    /*36*/ test("ggchha", "231/564/978");
    /*37*/ test("gfbkeg", "128/534/697");
    /*38*/ test("agfbcbf", "239/148/765");
    /*39*/ test("ekahijf", "123/645/789");
    /*40*/ test("hajdjbe", "789/432/615");
    /*41*/ test("elgililj", "976/325/814");
    /*42*/ test("chffefif", "317/629/845");
    /*43*/ test("ilbbihak", "462/587/319");
    /*44*/ test("abcdefghijkl", "123/456/789");
    /*45*/ test("hkijbglfaced", "768/125/493");
    /*46*/ test("dfkbjiechlga", "256/387/419");
    /*47*/ test("hgfkbidlajce", "186/745/239");
    /*48*/ test("baciefjhgkdl", "153/482/796");
}

int main()
{
    test_all();
    return 0;
}