#include "stdio.h"
#include "stdlib.h"
#define ex EOF
void recom()
{
 char a,b;
 a=getchar();
l:
 if(a==ex) {printf("NO\n");exit(0);}
 b=getchar();
 if(a=='*' && b==')') return;
 a=b;
 goto l;
}

main()
{
 char a,b;
 int k=0;
 a=getchar();
 while(a!=ex)
 {
  b=getchar();
  if(a=='(' && b=='*')
  {
   recom();
   a=getchar();
   continue;
  }
  if(a=='(')
  {
   k++;
   a=b;
   continue;
  }
  if(a==')')
  {
   if(k==0) {printf("NO\n");return 0;}
   k--;
   a=b;
   continue;
  }
  if(k!=0 && a!='\n' && a!='\r' && a!='=' && a!='+' && a!='-' && a!='*'
  && a!='/' && a<'0' && a>'9') {printf("NO\n");return 0;}
  a=b;
 }
 if(k!=0) printf("NO\n");
 else printf("YES\n");
}

Edited by author 13.02.2005 06:54

Be careful. Arithmetic expressions can't contain english letters. Try this test:

(1+a=2)

Thank you!!

Edited by author 16.02.2005 12:41

Thanks, got AC now ^_^