Question

In C++, write two functions named printArray and deleteRepeats along with a main to test them according to the following specifications. Be sure to use function prototypes and place the actual function definitions after main.

printArray will take two parameters: an array of characters and an integer representing the number characters stored in the array. It will print the characters from the array, labeled by their index, to the screen up to the specified size.

deleteRepeats will take the same two parameters, except that the integer must be passed by reference. The function must remove any repeated characters from the array and reduce the size to match the reduced number of characters. The contents of the array beyond the newly reduced size do not matter.

main must test deleteRepeats with 4 different sets of data. For each test, you will print the array, call deleteRepeats, and then print the array again. One data set must contain only unique characters. One data set must contain one character repeated several times. Two will be different mixtures of characters, including some repetition. Make sure at least of your arrays is completely full to start with and that at least one of them is not completely full to start with.

There should be no user interaction in this program.

Answer 1

#include <iostream>
#include <cstdlib>                                                        // Must be included to use the rand function, in this program
using namespace std;

void generateRandomCharacters(char *s, int arraySize);                                          // Generate random characters prototype

void printCharacterFrequency(char *s, int arraySize);                                           // Print character frequency prototype

void deleteRepeats(char *s, int &arraySize);                                                                // Delete repeats prototype

void printArray(char *s, int arraySize);                                                                        // Print array prototype

int main()
{
        char cArray[1000];
        int arrayLength = 1000;                                                 // Limiting array length to 1000
        
        srand(100);                                                                             // This sets a specific sequence of random numbers
        
        generateRandomCharacters(cArray, arrayLength);  // Generates random freqyency
        
        cout << "\nThe Random Array:\n";  
        printArray(cArray, arrayLength);                                // Prints 1000 "random" characters
        
        printCharacterFrequency(cArray, arrayLength);   // Pritns Char and Frequency table

        deleteRepeats(cArray, arrayLength);                             // Deletes all the repeated characters
        
        cout << "\nThe Compressed Array:\n";
        printArray(cArray, arrayLength);                                // Prints new list of "random" characters, without repeats
        
                printCharacterFrequency(cArray, arrayLength); // Prints the new Char and Frequency table after delete

        return 0;
}

/*
Generate Random Characters

This function takes in an array parameter to an array of characters and an integer corresponding to
the size of the array. The function then populates the array with randomly generated characters.

Using the rand function, it generate random numbers from 97 to 122, then converts them to characters

*/
void generateRandomCharacters(char *s, int arraySize)
{
        int num;
        
        for (int i = 0; i < arraySize; i++)
        {
                num = 97 + rand() % 26;
                s[i] = static_cast<char>(num);
        }
}

/*
Print Character Frequency

This function takes in an array parameter to an array of characters and an integer corresponding to 
the size of the array. This function then counts the occurrences (frequency) of each character in the array.

*/
void printCharacterFrequency(char *s, int arraySize)
{
        int freq[26];
        int i = 0;
        int iCount = 0;
        char findChar;
        int cumFreq = 0;
        
        for(iCount = 0; iCount < 26; iCount++)                                       // Initialize the array "freq"
                freq[iCount] = 0;
        
        for(iCount = 0; iCount < 26; iCount++)
        {
                findChar = static_cast<char>(97 + iCount);
        
                for(i = 0; i < arraySize; i++)
                {
                        if(findChar == s[i])
                                freq[iCount]++;
                }
        }
        
        cout << "\nFrequency Table:\nChar \tFrequency\n";         // Frequency Table output
        for(iCount = 0; iCount < 26; iCount++)
        {       
                cout << static_cast<char>(97 + iCount) << "\t" << freq[iCount] << "\t";
                cumFreq = cumFreq + freq[iCount];
                cout << cumFreq << "\n";
        }
}

/*
Delete Repeats

This function takes two parameters: a char array parameter pointing to the array of characters 
and an int reference parameter indicating the number of elements used in the array.

*/
void deleteRepeats(char *s, int &arraySize)
{
        int startPos = 0;
        int nDeleted = 0;
        
        while(startPos < arraySize)
        {
                nDeleted = 0;
                for(int i = startPos + 1; i < arraySize; i++)
                {
                        if(s[i] == s[startPos])
                                nDeleted++;
                        else
                                s[i - nDeleted] = s[i];
        
                }
                arraySize -= nDeleted;
                startPos++;
        }
}

/*
Print Array

Prints the characters generated by the generateRandomCharacter function.

*/

void printArray(char *s, int arraySize)
{
        for (int i = 0; i < arraySize; i++)
        {
                cout << s[i];
        }
        cout << "\n";
}