// Input two strings s and t from the user.  Assume that the strings do not
// contain blank or any whitespace character.
// Write a function that concatenates t to s, i.e., it modifies s by appending t to it.
// The parameters of the function concat contains only pointers to characters (not
// arrays):
// 	void concat(char *s, char *t)

//Author:rahule@iitk.ac.in

#include<stdio.h>

void concat(char *s, char *t);
int string_length(char *);
main()
{
  char s[100],t[50];
  printf("\nEnter the string to be appended [s] :");	
  scanf("%s",s);
  printf("\nEnter the string  which the first string has to be appended with [t] :");
  scanf("%s",t);
  concat(s,t);		//conactinates t with s and stores the reulst in S
  printf("Modified String is : %s\n",s);
}


void concat(char *s, char *t)
//concatinates strings pointed by the pointers s,t
{
  int l;
  l=string_length(s);	//find the length of string S
  s=s+l;	//pointer to the first string is moved to the end of the string
  while(*t != '\0')	//till the end of second string,do the followig
  {
    *s=*t;	//copy the contents of t to s
    s++;
    t++;
  }
  *s='\0';	//to make the new appended string in s valid,append a '\0' at the end
}


int string_length(char *s)
//function to find the string length
{
  int i;
  for(i=0;s[i]!='\0';i++);	//loop until s[i] = '\0'
  return(i);
}