// © 2021 SoloLearn Community #include #include // std::reverse, std::swap constexpr size_t ROWS { 3 }, COLS { 5 }; // reverse elements of row of void reverse_row( int** matrix, const size_t row_index ) { // swap left (L) and right (R) elements for (size_t L { 0 }, R { COLS - 1 }, M { COLS / 2 }; L < M; L++, R--) { // std::swap( matrix[ row_index ][ L ], matrix[ row_index ][ R ] ); int swap = matrix[ row_index ][ L ]; matrix[ row_index ][ L ] = matrix[ row_index ][ R ]; matrix[ row_index ][ R ] = swap; } } // reverse elements of column of void reverse_column( int** matrix, const size_t column_index ) { // swap top (T) and bottom (B) elements for (size_t T { 0 }, B { ROWS - 1 }, M { ROWS / 2 }; T < M; T++, B--) { // std::swap( matrix[ T ][ column_index ], matrix[B ][ column_index ] ); int swap = matrix[ T ][ column_index ]; matrix[ T ][ column_index ] = matrix[ B ][ column_index ]; matrix[ B ][ column_index ] = swap; } } // prints void print( int** matrix) { for( size_t i { 0 }, j; i < ROWS; i++ ) { std::cout << "{ " << matrix[ i ][ 0 ]; for( j = 1; j < COLS; j++ ) { std::cout << ", " << matrix[ i ][ j ]; } std::cout << " }\n"; } std::cout << "\n"; } int main() { int** matrix{ new int*[ ROWS ] }; int v{ ROWS * COLS }; size_t i, j; // populate the matrix with , gradually decrementing value std::cout << "Original array (" << ROWS << " x " << COLS << ")\n"; for( i = 0; i < ROWS; i++ ) { matrix[ i ] = new int[ COLS ]; for( j = 0; j < COLS; j++ ) { matrix[ i ][ j ] = v--; } } print( matrix ); // now we reverse elements row wise std::cout << "After reversing the rows:\n"; for( i = 0; i < ROWS; i++ ) { //std::reverse( matrix[ i ], matrix[ i ] + COLS ); reverse_row( matrix, i ); } print( matrix ); // and now we reverse elements column wise std::cout << "After reversing the columns:\n"; for( i = 0; i < COLS; i++ ) { reverse_column( matrix, i ); } print( matrix ); // now that we're done, let's do some housekeeping for( i = 0; i < ROWS; i++ ) { delete [] matrix[ i ]; } delete [] matrix; return 0; }

Reverse array elements row and/or column wise