#include <iostream>

using namespace std;

int main()
{
   int N,z=0,z1,z2;
   int x1,y1,x2,y2,x3,y3;
   cin >> N >> x1 >> y1 >> x2 >> y2;
   N-=2;
   int xx1=x1,yy1=y1;
   x1 =x2 - x1;
   y1 =y2 - y1;
   int xx=x1,yy=y1;
   while (N--)
   {
       cin >> x3 >> y3;
       z1 =x3 - x2;
       z2 =y3 - y2;
       z+= x1*z2-z1*y1;
       x1 = z1;
       y1 = z2;
       x2 = x3;
       y2 = y3;
   }
   z1 = xx1-x3;
   z2 = yy1-y3;
    z+= z1*yy-z2*xx;
   if (z<0)
       cout << "cw";
   else
       cout << "ccw";
   return 0;
}

Edited by author 24.08.2007 15:33

I think you've forgotten about the 1st and nth points) And also you should write something like z += ... to count the total direction)
Good Luck!))

Edited by author 24.08.2007 08:57

I had the same problem. But when I replaced "int" with "double", I've got AC. Just try to calculate next expression: 50000*50000 - 50000*(-50000) = ???????????