PROGRAM TO CHECK A VOWEL OR CONSONANT :

#include <stdio.h>
int main()
{
    char c;
    int LowercaseVowel, UppercaseVowel;
   
    printf("Enter an alphabet: ");
    scanf("%c",&c);
   
   LowercaseVowel = (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u');
    UppercaseVowel = (c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U');
   
   if (LowercaseVowel || UppercaseVowel)
        printf("%c is a vowel ", c);
    else
        printf("%c is a consonant ", c);
   
    return 0;
}

OUTPUT :

Enter an alphabet : apurba
a is a vowel

Enter an alphabet : Crazycoder
C is a consonant