Programming Challenge 1

#include <iostream>
#include <cstring>
#include <cctype>
using namespace std;

void separate(char *);
void sort(char *, int );

char in[100], vOut[100], cOut[100];

int main()
{
    cout << "Enter a word: ";
    cin.getline(in, 100);

    separate(in);

    sort(vOut, 1);
    sort(cOut, 0);

    cout << endl << "Vowels: " << vOut << endl;
    cout << "Consonants: " << cOut << endl << endl;

    system("PAUSE");
    system("cls");
    main();
}

void separate(char * input)
{
    int vCount = 0, cCount = 0, length = strlen(input);

    for(int i = 0; i < length; i++)
    {
        if( input[i] == 'a' || input[i] == 'A' ||
            input[i] == 'e' || input[i] == 'E' ||
            input[i] == 'i' || input[i] == 'I' ||
            input[i] == 'o' || input[i] == 'O' ||
            input[i] == 'u' || input[i] == 'U' )
        {
            vOut[vCount] = tolower(input[i]);
            vCount++;
        }
        else if(isalpha(input[i]) == 0)
        {
            // ignore characters that aren't letters
        }
        else
        {
            cOut[cCount] = tolower(input[i]);
            cCount++;
        }
    }
}

void sort(char * input, int isVowel)
{
    int length = strlen(input);

    for(int i = 0; i < length; i++)
    {
        for(int j = 0; j < length-1; j++)
        {
            if(input[j + 1] < input[j])
            {
                char temp = input[j + 1];
                input[j + 1] = input[j];
                input[j] = temp;
            }
        }
    }

    if(isVowel == 1)
    {
        for(int i = 0; i < length; i++)
        {
            vOut[i] = input[i];
        }
    }
    else
    {
        for(int i = 0; i < length; i++)
        {
            cOut[i] = input[i];
        }
    }
}