#include
int main()
{unsigned long int i=0;
char ch;
char name1[20],name2[20];
FILE *fp,*ft;
printf("ENTER THE SOURCE FILE:");
gets(name1);
printf("ENTER THE DESTINATION FILE:");
gets(name2);
fp=fopen(name1,"r");
ft=fopen(name2,"w");
if(fp==NULL)
{printf("CAN,T OPEN THE FILE");
}
while(!feof(fp))
{ch=getc(fp);
ch=~((ch^i));
i+=2;
if(i==100000)
{i=0;
}
putc(ch,ft);
}
fclose(fp);
fclose(ft);
return 0;
}