#include <stdio.h>

int main ( int argc, char* argv [] )
{
	char ch = '0';
	int nvalue = 0;
	while ( 1 ) {
		printf ("\n Enter the alphabet or press 0 
to exit :");
		scanf ( "%c", &ch );
		if ( ch == '0' ) break;
		nvalue = ( ( (int) 'a' <= (int) ch ) && ( 
(int) 'z' >= (int) ch ) ) 
			 ? ~( (int) 'a' - (int) ch ) + 2
			: ( ( (int) 'A' <= (int) ch ) && ( 
(int) 'Z' >= (int) ch ) )
			? ~( (int) 'A' - (int) ch ) + 2
			: 0;
		printf ("\n The Value :%d", nvalue );
	}

	return ( 0 );
}

#include<stdio.h>
#include<conio.h>
void main()
{
clrscr();
char ch;
int no;
printf("Enter the charactor:");
scanf("%c",&ch);
if(int(ch)>=65&&int(ch)<=91)
{
no=int(ch)-64;
printf("%d\n",no);
}
if(int(ch)>=97&&int(ch)<=123)
{
no=int(ch)-96;
printf("%d\n",no);
}
getch();
}

#include<stdio.h>
#include<conio.h>
void main()
{
char s;
printf("enter the character :");
scanf("%d",&s);
printf("\n here CAPITAL and SMALL letters are taken as same\n");
if(s>='A'&&s<='Z')
printf("\nthis is the %dth alphabet from first",s-'A');
else if(s>='a'&&s<='z')
printf("\nthis is the %dth alphabet from first",s-'a');
else
printf("\n INVALID ALPHABET");
getch();
}


thank u

#include<stdio.h>
int main()
{
    char c;
    int i;
    printf("Enter any char\t");
    scanf("%c",&c);
    if ( c>=65 && c<=92)

        printf("%d\n",c-64);

    else if( c>=97 && c<=122)

        printf("%d\n",c-96);
    else
        printf("\n\nWrong Input\n\n");

}