# Sample solution

#include <cstddef> /* needed for std::size_t and std::ptrdiff_t */
#include <utility> /* needed for std::swap */
#include <printf.hpp> /* needed for fmt::printf */

struct Matrix {
std::size_t m; /* number of rows */
std::size_t n; /* number of columns */
std::ptrdiff_t incRow;
std::ptrdiff_t incCol;
double* data;

void init() {
for (std::size_t i = 0; i < m; ++i) {
for (std::size_t j = 0; j < n; ++j) {
data[i*incRow + j*incCol] = j * m + i + 1;
}
}
}

void print() {
for (std::size_t i = 0; i < m; ++i) {
fmt::printf("  ");
for (std::size_t j = 0; j < n; ++j) {
fmt::printf(" %4.1lf", data[i*incRow + j*incCol]);
}
fmt::printf("\n");
}
}
};

void transpose(Matrix& A) {
std::swap(A.m, A.n);
std::swap(A.incRow, A.incCol);
}

int main() {
Matrix A;
A.m = 7; A.n = 8;
A.data = new double[A.m * A.n];
A.incRow = 1; A.incCol = 7;
A.init();
fmt::printf("A =\n"); A.print();
transpose(A);
fmt::printf("A^T =\n"); A.print();
}

theon$g++ -std=gnu++11 -o call5 call5.cpp theon$ ./call5
A =
1.0  8.0 15.0 22.0 29.0 36.0 43.0 50.0
2.0  9.0 16.0 23.0 30.0 37.0 44.0 51.0
3.0 10.0 17.0 24.0 31.0 38.0 45.0 52.0
4.0 11.0 18.0 25.0 32.0 39.0 46.0 53.0
5.0 12.0 19.0 26.0 33.0 40.0 47.0 54.0
6.0 13.0 20.0 27.0 34.0 41.0 48.0 55.0
7.0 14.0 21.0 28.0 35.0 42.0 49.0 56.0
A^T =
1.0  2.0  3.0  4.0  5.0  6.0  7.0
8.0  9.0 10.0 11.0 12.0 13.0 14.0
15.0 16.0 17.0 18.0 19.0 20.0 21.0
22.0 23.0 24.0 25.0 26.0 27.0 28.0
29.0 30.0 31.0 32.0 33.0 34.0 35.0
36.0 37.0 38.0 39.0 40.0 41.0 42.0
43.0 44.0 45.0 46.0 47.0 48.0 49.0
50.0 51.0 52.0 53.0 54.0 55.0 56.0
theon\$