a program that would accept a stream of characters as input and display only the letters removing the spaces. Convert all vowels to uppercase and all consonants to lowercase.

/******************************************************************************

Write a program that would accept a stream of characters as input and  display only the letters removing the spaces. Convert all vowels to uppercase and  all consonants to lowercase.

     Sample Output:   

Enter a stream of characters:       Hello    World    123!!!

                                 hEllOwOrld

*******************************************************************************/
#include <stdio.h>
#include <ctype.h>
#include <string.h>

char Determine_Cons_Vow (char *S);
char Remove_Space_Number (char *S);
char String[100], No_Space_Number[100], Cons_Vow_String[100];
int main()
{
    printf("Input a string of characters: ");
    scanf("%[^\n]%*c", String);
    
    printf ("Before:                     %s\n", String);
    
    Remove_Space_Number(String);
    
    printf ("Without Spaces and Numbers: %s\n", No_Space_Number);
    
    Determine_Cons_Vow(No_Space_Number);
    
    printf ("Final:                      %s", Cons_Vow_String);
    
    return 0;
}

char Remove_Space_Number(char *S)
{
    
    int j=0;
    for (int i=0; i<=100; i++)
    {
        if (String[i] != ' ')
        {
            if (isalpha(String[i]))
            {
                No_Space_Number[j]=String[i];
                j++;
            }
        }
    }
    for (int i=0; i<=100; i++)
    {
        return No_Space_Number[i];
    }
}

char Determine_Cons_Vow (char *S)
{
    int j=0;
    
    for (int i=0; i<=100; i++) 
    {
        Cons_Vow_String[i]=No_Space_Number[i];
    }
    
    for (int i=0; i<=100; i++)
    {
        if (Cons_Vow_String[i] == 'a' || Cons_Vow_String[i] == 'e' || Cons_Vow_String[i] == 'i' ||Cons_Vow_String[i] == 'o' || Cons_Vow_String[i] == 'u' || Cons_Vow_String[i] == 'A' || Cons_Vow_String[i] == 'E' || Cons_Vow_String[i] == 'I' || Cons_Vow_String[i] == 'O' || Cons_Vow_String[i] == 'U') 
        {
            Cons_Vow_String[i] = toupper(Cons_Vow_String[i]);
        }
        else
        Cons_Vow_String[i] = tolower(Cons_Vow_String[i]);
    }
    
    for (int i=0; i<=100; i++)
    {
        return Cons_Vow_String[i];
    }
}