REVERSE A STRING USING A STACK

Aim:
To reverse a string using a stack.
Program:
#include
#include
#include
#define MAX 20
int top = -1;
char stack[MAX];
char pop();
void push(char);
main()
{
 char str[20];
 unsigned int i;
 printf(“Enter the string : ” );
 gets(str);

 for(i=0;i<strlen(str);i++)
 push(str[i]);
 for(i=0;i<strlen(str);i++)
 str[i]=pop();
 printf(“Reversed string is : “);
 puts(str);
}
void push(char item)
{
 if(top == (MAX-1))
 {
 printf(“Stack Overflow\n”);
 return;
 }
 stack[++top] =item;
}
char pop()
{
 if(top == -1)
 {
 printf(“Stack Underflow\n”);
 exit(1);