Activecode Exercises

Answer the following Activecode questions to assess what you have learned in this chapter.

Write the enumerated type Days which maps days of the week to integers starting at 1. Use a switch statement to determine whether or not day is a weekend or not. Check for cases in numerical order.

#include <iostream> using namespace std; // YOUR CODE HERE

Below is one way to use a switch statement to classify a day of the week.

#include <iostream> using namespace std; enum Day { MON = 1, TUE, WED, THU, FRI, SAT, SUN }; int main () { Day day = SUN; switch (day > 5) { case 0: cout << "It is not the weekend :(" << endl; break; case 1: cout << "It is the weekend :)" << endl; break; default: cout << "Invalid input." << endl; break; } }

Use a switch statement to check and print out whether a number is divisible by two. Prompt and get input from the user. If input isn’t valid, print out the default statement “Invalid input.” Check for cases in numerical order.

#include <iostream> using namespace std; // YOUR CODE HERE

Below is one way to use a switch statement to check and print out whether a number is divisible by two.

#include <iostream> using namespace std; int main () { int input; cout << "Please enter an integer: "; cin >> input; switch (input % 2) { case 0: cout << input << " is even!" << endl; break; case 1: cout << input << " is odd!" << endl; break; default: cout << "Invalid input." << endl; break; } }

Use a switch statement to check and print out the maximum between two numbers. Prompt and get input from the user for two integers. If input isn’t valid, print out the default statement “Invalid input.” Check for cases in numerical order.

#include <iostream> using namespace std; // YOUR CODE HERE

Below is one way to use a switch statement to check and print out the maximum between two numbers.

#include <iostream> using namespace std; int main () { int input1; int input2; cout << "Please enter first integer: "; cin >> input1; cout << "Please enter second integer: "; cin >> input2; switch (input1 > input2) { case 0: cout << "The maximum is " << input2 << endl; break; case 1: cout << "The maximum is " << input1 << endl; default: cout << "Invalid input." << endl; break; } }

Write the pseudocode for the implementation of mergeSort.

// YOUR PSEUDOCODE HERE

Below is one way to write the pseudocode of mergeSort.

Deck Deck::mergeSort () const { find the midpoint of the deck divide the deck into two subdecks sort the subdecks using sort merge the two halves and return the result divide each subdeck into two more subdecks }

Let’s revisit the Dictionary data structure defined in the previous section. Write the struct definitions for Entry, which has member variables word and page, and for Dictionary, which has a vector of Entries.

#include <iostream> #include <vector> using namespace std; // YOUR CODE HERE

Below is one way to write the struct definition for Entry and for Dictionary.

#include <iostream> #include <vector> using namespace std; struct Entry { string word; int page; }; struct Dictionary { vector<Entry> entries; };

Assume our dictionary is currently unsorted. Let’s write a Dictionary member function find that takes a string word as a parameter and returns the index of its corresponding entry. If the word isn’t in the dictionary, return -1.

#include <iostream> #include <vector> using namespace std; // YOUR CODE HERE

Below is one way to write the Dictionary member function.

#include <iostream> #include <vector> using namespace std; struct Entry { string word; int page; }; struct Dictionary { vector<Entry> entries; }; int Dictionary::find (string word) { for (size_t i = 0; i < entries.size(); ++i) { if (entries[i].word == word) { return i; } } return -1; }

Of course, all dictionaries are in some sort of order. In order to do this, we must first write the Dictionary member function findFirstWord, which takes a starting index as a parameter returns the index of the Entry with the highest priority alphabetically (i.e. the Entry with a word that would come first in the alphabet).

#include <iostream> #include <vector> using namespace std; // YOUR CODE HERE

Below is one way to write the findFirstWord member function.

#include <iostream> #include <vector> using namespace std; struct Entry { string word; int page; }; struct Dictionary { vector<Entry> entries; }; int Dictionary::findFirstWord (int start) { int min = start; for (size_t i = start; i < entries.size(); ++i) { if (entries[i].word < entries[min].word) { min = i; } } return min; }

We also need a swap function. Write the Dictionary member function swap which takes two indices as parameters and swaps the Entries at those indices.

#include <iostream> #include <vector> using namespace std; // YOUR CODE HERE

Below is one way to write the swap member function

#include <iostream> #include <vector> using namespace std; struct Entry { string word; int page; }; struct Dictionary { vector<Entry> entries; }; void Dictionary::swap (int a, int b) { Entry temp = entries[a]; entries[a] = entries[b]; entries[b] = temp; }

Now let’s write the Dictionary member function alphabetize, which sorts the Entries in the Dictionary in alphabetical order. Use the findFirstWord and swap functions we defined earlier!

#include <iostream> #include <vector> using namespace std; // YOUR CODE HERE

Below is one way to write the Dictionary member function alphabetize.

#include <iostream> #include <vector> using namespace std; void Dictionary::alphabetize () { for (size_t i = 0; i < entries.size(); ++i) { int min = findFirstWord (i); swap (i, min); } }

Let’s check to see if our sorting worked! Write the Dictionary member function printDictionary, which prints out the word in each Entry.

#include <iostream> #include <vector> using namespace std; // YOUR CODE HERE

Below is one way to write the Dictionary member function printDictionary.

#include <iostream> #include <vector> using namespace std; struct Entry { string word; int page; }; struct Dictionary { vector<Entry> entries; }; void Dictionary::printDictionary () { for (size_t i = 0; i < entries.size(); ++i) { cout << entries[i].word << endl; } }

You have attempted of activities on this page