in an input string
#include 
#include 
int strindex(char s[],char t);
void main()
{
 char s[80],t;
 int a=0;
 clrscr();
 printf("
Enter main string(i.e. s):-
");
 gets(s);
 printf("
Enter the character to be searched(i.e. t):- ");
 t=getchar();
 a=strindex(s,t);
 if (a>=0)
 printf("
The required character is found at position %d.",a);
 else
 printf("
The required character is not found in the string.");
 getch();
}
int strindex(char s[],char t)
{
 int i=0;
 for (i=strlen(s);i>=0;i--)
 {
 if (s[i]==t)
	return(i);
 }
if (i<0)
	return(-1);
}