#include <library.h>

void find_sqrt(int a, int b, int x)  // want square root of x, given
                                     // that it will be between a and b
{ const int mid = (a+b)/2;
  cout << "my guess is " << mid << "\n";
  if (mid*mid == x)
    cout << "I won\n";
  else if (mid*mid > x)
    find_sqrt(a, mid-1, x);
  else
    find_sqrt(mid+1, b, x); }

void main()
{ find_sqrt(0, 1000, 6400); }

// the mistake on Thursday was that I'd typed this
// { guess_at(0, 1000000, 6400); }
// so the first guess was mid = 500000, and that gives
// mid*mid = 250000000000, which is far too big to fit
// in an int.