/*
Summary: Find how many number of vowels are present in a string.
*/

#include<stdio.h>

int count_vowels(char []);
int check_vowel(char);

int main()
{
 char array[100];
 int c;

 printf("Enter a string\n");
 gets(array);

 c = count_vowels(array);

 printf("Number of vowels: %d\n", c);

 return 0;
}

int count_vowels(char a[])
{
 int count = 0, c = 0, flag;
 char d;
 do
 {
  d = a[c];
  flag = check_vowel(d);
  if ( flag == 1 )
   count++;
  c++;
 }while( d != '\0' );

 return count;
}

int check_vowel(char a)
{
 if ( a >= 'A' && a <= 'Z' )
        a = a + 'a' - 'A';   /* Converting to lower case */
    if ( a == 'a' || a == 'e' || a == 'i' || a == 'o' || a == 'u')
        return 1;

    return 0;
}