Перестановка столбцов матрицы

#include <iostream>
#include <valarray>
#include <random>
#include <iomanip>
#include <numeric>
#include <algorithm>

using namespace std;

int randomize();
void random_fill(valarray<int>& matrix);
void print(valarray<int>& matrix, const size_t columns, const streamsize width = 5);
void print(valarray<int>& line, const streamsize width = 5);
valarray<int> permutation(valarray<int>& matrix, const size_t rows, const size_t columns);
int specification(valarray<int>& column);
int sum(valarray<int>& column);
void print_sum(valarray<int>& matrix, const size_t rows, const size_t columns, const streamsize width = 5);

int main() {
    setlocale(LC_CTYPE, "Russian");

    cout << "\n\t Введите количество строк матрицы: ";
    size_t rows;
    cin >> rows;

    cout << "\t Введите количество столбцов матрицы: ";
    size_t columns;
    cin >> columns;

    size_t size = rows * columns;
    valarray<int> matrix(size);

    random_fill(matrix);
    print(matrix, columns);
    valarray<int> spec = permutation(matrix, rows, columns);
    print(matrix, columns);
    print(spec);
    print_sum(matrix, rows, columns);

    cin.sync();
    cin.get();
}

int specification(valarray<int>& column) {
    return abs(accumulate(begin(column), end(column), 0, [](int sum, int next) { return next < 0 ? sum + next : sum; }));
}

int sum(valarray<int>& column) {
    return accumulate(begin(column), end(column), 0);
}

void print_sum(valarray<int>& matrix, const size_t rows, const size_t columns, const streamsize width) {
    valarray<int> temp;

    cout << endl;

    for (size_t index = 0; index < columns; ++index) {
        slice slise_matrix(index, rows, columns);
        temp = matrix[slise_matrix];
        if (specification(temp)) cout << setw(width) << sum(temp);
        else cout << setw(width) << '-';
    }

    cout << endl;
}

valarray<int> permutation(valarray<int>& matrix, const size_t rows, const size_t columns) {
    valarray<int> specifications(columns);
    valarray<valarray<int>> temp(columns);

    for (size_t index = 0; index < columns; ++index) {
        slice slise_matrix(index, rows, columns);
        temp[index] = matrix[slise_matrix];
        specifications[index] = specification(temp[index]);
    }

    print(specifications);

    for (size_t n = 1; n < columns; ++n)
        for (size_t m = 0; m < columns - n; ++m)
            if (specifications[m] > specifications[m + 1]) {
                swap(specifications[m], specifications[m + 1]);
                swap(temp[m], temp[m + 1]);
            }

    for (size_t j = 0, k = 0; j < rows; ++j) for (size_t i = 0; i < columns; ++i) matrix[k++] = temp[i][j];

    return specifications;
}

void print(valarray<int>& line, const streamsize width) {
    cout << endl;
    for (auto element : line) cout << setw(width) << element;
    cout << endl;
}

void print(valarray<int>& matrix, const size_t columns, const streamsize width) {
    size_t column = 0;

    cout << endl;

    for (auto element : matrix) {
        cout << setw(width) << element;
        if (++column % columns) continue;
        cout << '\n';
    }
}

void random_fill(valarray<int>& matrix) {
    generate(begin(matrix), end(matrix), randomize);
}

int randomize() {
    uniform_int_distribution<int> rand(-10, 10);
    random_device rnd;
    return rand(rnd);
}