OJ Board

#include<cstdio>

using namespace std;
typedef struct
{
int top;
char items[1000];

}stack;
bool isempty(stack *s)
{
if(s->top==-1)
return true;
else
return false;

}
char push(stack *s,int data)
{

s->items[++s->top]=data;
}
char pop(stack *s)
{
if(!isempty(s))
return s->items[s->top ...