/* This program inverts a dynamically allocated 2D array * from top to bottom and displays the result. * * Demonstrates the use of: * dynamically allocated arrays in C++ using the new keyword * disposal of dynamic memory using delete * passing arrays to functions * std::swap() C++11 * * User Input for SoloLearn (3 x 3 array) 3 3 1 2 3 4 5 6 7 8 9 */ #include #include using namespace std; // declare functions void fillarray(int* a, int w, int h); void showarray(int* a, int w, int h); void invert (int* a,int w , int h); // Program entry point int main() { // declare variables int nrows, ncols; int* arr; // get array dimensions from user cout <<"enter number of rows in array:\n"; cin >> nrows; cout <<"enter number of columns in array:\n"; cin >> ncols; // dynamically allocate array arr = new int[nrows * ncols]; // get array values from the user fillarray(arr, ncols, nrows); // display the original array cout << endl << "== Original Array ==" << endl; showarray(arr, ncols, nrows); // invert the array invert(arr, ncols, nrows); // display the inverted array cout << endl << "== Inverted Array ==" << endl; showarray(arr, ncols, nrows); // delete the array delete []arr; // all done return 0; } /* Function to invert a 2D array from top to bottom * * Inputs: a - pointer to an array of integers * w - width of the array (columns) * h - height of the array (rows) * * Outputs: Nothing. Upon completion the array is * inverted from top to bottom in place. * */ void invert (int *a, int w, int h) { for (int i=0; i< h/2; i++){ for (int j=0; j> a[i * w + j]; } } } /* * The author of this work hereby waives all claim of copyright (economic * and moral) in this work and immediately places it in the public domain; * it may be used, distorted or destroyed in any manner whatsoever without * further attribution or notice to the creator. */

Invert a 2D Array