/*
 * To replace all occurrences of a substring t in s with w,using pointers
 * @author-Karan Narain(karan@iitk.ac.in)
 *
*/
#include <stdio.h>
int replace_substring(char *s,char *t,char *w)
{
	int i=0,index=-1,count=0;
	char *copy,*x,*y,*z;
	copy=s;
	while(*s!='\0')
	{
		if(*s==*t)
		{
			index=i;
			x=s;
			y=t;
			while(*x==*y && *x!='\0')
			{
				x++;
				y++;
			}
			//if t is present completely in s
			if(*y=='\0')
			{
				x=s;
				z=w;
				//replace t with w
				while(*z!='\0')
				{
					*x=*z;
					x++;
					z++;
				}
				count++;
			}
		}
		s++;
		i++;
	}
	printf("After replacement,string is %s\n",copy);
	return count;
}
int main()
{
	int count;
	char A[80],B[80],C[80],*s=NULL,*t=NULL,*w=NULL;
	printf("Enter the string s\n");
	scanf("%s",&A);
	printf("Enter the string t\n");
	scanf("%s",&B);
	printf("Enter the string w\n");
	scanf("%s",&C);
	s=A;
	t=B;
	w=C;
	count=replace_substring(s,t,w);
	printf("Replaced %d occurrences\n",count);
	return 0;

}