I got WA6 in this case:
if (inc1 == inc2) {
    cout << labs(cr2x - cr1x) + labs(cr2y - cr1y);
    return;
}
cout << max(labs(cr2x - cr1x), labs(cr2y - cr1y));

but I got AC in this case:
if (inc1 == inc2) {
    cout << (cr2x - cr1x) + labs(cr2y - cr1y);
    return;
}
cout << max(labs(cr2x - cr1x), labs(cr2y - cr1y));

and in this case:
if (inc1 == inc2) {
    cout << labs(cr2x - cr1x) + (cr2y - cr1y);
    return;
}
cout << max(labs(cr2x - cr1x), labs(cr2y - cr1y));

and in this:
if (inc1 == inc2) {
    cout << (cr2x - cr1x) + (cr2y - cr1y);
    return;
}
cout << max(labs(cr2x - cr1x), labs(cr2y - cr1y));

p.s. cr1x, cr1y, cr2x, cr2y is long long, (cr2x - cr1x)>=0 and (cr2y - cr1y)>=0 always, but why in this case does not labs() work correctly ?

  Letter 'l' in "labs" stands for "long" = "int" (not "long long").
  So in the first case two summands are converted from "long long" to "int" and the summation causes overflow.
  In the second and the third cases one of the summands has type "long long" so the sum is in type "long long" too.

Edited by author 12.04.2010 22:11