Program of reversing a string using stack

‪#‎include‬<stdio.h>
#include<string.h>
#include<stdlib.h>
‪#‎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);
/*Push characters of the string str on the stack */
for(i=0;i<strlen(str);i++)
push(str[i]);
/*Pop characters from the stack and store in string str */
for(i=0;i<strlen(str);i++)
{
str[i]=pop();
printf(“Reversed string is : “);
puts(str);
}/*End of main()*/
void push(char item)
{
if(top == (MAX-1))
{
printf(“Stack Overflow\n”);
return;
}
stack[++top] =item;
}/*End of push()*/
char pop()
{
if(top == -1)
{
printf(“Stack Underflow\n”);
exit(1);
}
return stack[top–];
}/*End of pop()*/