#include<stdio.h>
#include<stdlib.h>
 
typedefchar stackitem;
struct stack {
stackitem d;
struct stack *next;
};
typedefstruct stack ELEMENT;
typedef ELEMENT *POINTER;
 
 
 
void push(POINTER *Top, stackitem a)
/* put a into the top of the stack */
{
POINTER temp;
temp = malloc(sizeof(ELEMENT));
temp->d = a;
temp->next = *Top;
*Top = temp;
}
void push_string(POINTER *Top,char *string)
{
}
void pop(POINTER *Top)
{
POINTER Top1 = *Top;
if (*Top != NULL)
{
*Top = Top1->next;
free(Top1);
}
else
{
printf("Empty stack.\n");
}
}
 
void print_stack(POINTER Top){
POINTER copy= Top;
while(copy!=NULL)
{ 
printf("%c",copy->d);
copy=copy->next;
}
}
int main()
{
int i;
char buff[20];
POINTER start=NULL;
fgets(buff,20,stdin);

for(i=0;buff[i]!='\0';i++)
{
push(&start,buff[i]);
}
 
print_stack(start);
 

}

for(i=0;buff[i]!='\0';i++)
{
void push(POINTER *Top, stackitem a)
}

$ ./a.out 
this is a line
 
enil a si siht

void push_string(POINTER *Top,char *string)
{
  int i = 0;  // for indexing string
  while(string[i]) // while not end of string
  {
    push(Top, string[i]); // push item
    i++; // increment
  }
}

int main()
{
int i;
char buff[20];
POINTER start=NULL;
fgets(buff,20,stdin);

for(i=0;buff[i]!='\0';i++)
{
push_string(&start,buff);
//push(&start,buff[i]);
}
 
print_stack(start);
 

}

int main()
{
   int i;
   char buff[20];
   POINTER start=NULL;
   fgets(buff,20,stdin);
 
   //add buff to stack from within main()
   for(i=0;buff[i]!='\0';i++)
   {
        push(&start,buff[i]);
   }
 
   //print stack
   print_stack(start);
 
   //delete stack
   delete_stack(&start);
 
   //add buff to stack from within push_string()
   push_string(&start, buff);
 
   //print stack
   print_stack(start);
 
   //delete stack
   delete_stack(&start);
}

delete_stack(POINTER *TOP)
{
POINTER TEMP2;
while (Top !=NULL)
                  {
TEMP2= Top;
Top=Top->next;
delete TEMP2;
                    }
}

delete_stack(POINTER *TOP)
{
POINTER TOP3;
while (Top !=NULL)
{
  pop(Top);
*Top = Top3->next;
  }
}

while(Top)
  pop(Top);