The C++Course provides a general introduction to programming in C++. It is based on A.B. Downey's book, How to Think Like a Computer Scientist. Click here for details. 
Home File Input/Output and pmatrices A Distance Matrix  
A Distance Matrix
We'll create the matrix in main, with plenty of space to spare: pmatrix<int> distances (50, 50, 0);Inside processLine, we add new information to the matrix by getting the indices of the two cities from the Set and using them as matrix indices: int dist = convertToInt (distString);int index1 = cities.add (city1); int index2 = cities.add (city2); distances[index1][index2] = distance; distances[index2][index1] = distance; Finally, in main we can print the information in a humanreadable form: for (int i=0; i<cities.getNumElements(); i++) {cout << cities.getElement(i) << "\t"; for (int j=0; j<=i; j++) { cout << distances[i][j] << "\t"; } cout << endl; } cout << "\t"; for (int i=0; i<cities.getNumElements(); i++) { cout << cities.getElement(i) << "\t"; } cout << endl; This code produces the output shown at the beginning of the chapter. The original data is available from this book's web page.


Home File Input/Output and pmatrices A Distance Matrix 