i have got WA on test #5. Help me please. Thanks

[code deleted]
My first submit got WA#8, my second WA#9, my third got WA#10 of course. I  am going so straight,  so incrementally.  Maybe author made tests in such an amazing increasing-difficulty way.

Edited by moderator 03.12.2019 21:46

You can solve this problem in integers, without any angles.

input#1:
30000 30000 29999 -29999 -30000
12
19999 19996
19999 19997
19999 19998
19999 19999
19999 20000
19999 20001
19999 20002
19999 20003
19998 19996
19998 19997
19998 19998
19998 19999

output#1:
YES
YES
YES
NO
NO
NO
NO
NO
YES
YES
NO
NO

input#2:
30000 29999 30000 -30000 -29999
12
19999 19996
19999 19997
19999 19998
19999 19999
19999 20000
19999 20001
19999 20002
19999 20003
19998 19996
19998 19997
19998 19998
19998 19999

ouput#2:
NO
NO
NO
NO
YES
YES
YES
YES
NO
NO
NO
YES

It's better to count angles like there --> arccos((x1*x2+y1*y2)/(rast(x1,y1)*rast(x2,y2)));
Be carefull when cos is ~1. Good luck!

Hahaha I got WA#1 so many times just because i didn't notice that letters should be big))))

const
  eps = 1e-9;
var
  a1, b1, a2, b2, x, y, x1, y1, d, x2, y2: real;
  i, n: longint;
Begin
  read(d, x1, y1, x2, y2);
  read(n);
  a1 := y1;
  b1 := -x1;
  a2 := y2;
  b2 := -x2;
  for i := 1 to n do begin
    read(x, y);
    if (abs(x1 - x2) < eps) and (abs(y1 - y2) < eps)
    then begin if (abs(a1 * x + b1 * y) < eps) and (x * x + y * y - eps <= d * d) and (abs(sqrt(x * x + y * y) + sqrt((x - x1) * (x - x1) + (y - y1) * (y - y1)) - sqrt(x1 * x1 + y1 * y1)) < eps)
      then writeln('YES')
      else writeln('NO')
    end
    else if (a1 * x + b1 * y - eps <= 0) and (a2 * x + b2 * y + eps >= 0) and (x * x + y * y - eps <= d * d)
      then writeln('YES')
      else writeln('NO');
  end;
End.

I solve this problem with type longint but it makes no difference...

In statement: 1 <= |X1| , |Y1|, |X2|, |Y2| <= 30000
0 <= |Xi|, |Yi| <= 30000

In test 6 there is number with absolute value 30001. This number cannot cause overflow, but it is not good that the test does not correspond to the statement.

Test 3: arc of fire is 0 degrees. So arc of fire 0 degrees is pretty legal.

But! I know many AC solutions that think that when arc of fire 0 degrees gnusmasses in _opposite_ direction will be killed.

Test
100 1 0 1 0
1
-1 0

YES is wrong answer.

I suggest to remove test with arc of fire 0 degrees and to write in statement that arc of fire strictly greater than 0. And add to timus problemset problem "Good Gnusmas – Dead Gnusmas. Version 2" without any limitations on size of arc of fire i.e. with limitation [0; 360) degrees. Arc greater than 180 degrees can be defined quite well because we know that first range is left and the second is right.

Edited by author 19.01.2009 12:29

rus: "координаты точек соответственно на правой и левой границах обстрела."

eng: "coordinates of the right and the left bounds of the arc of fire."

It is problem from school championship so Russian text is original. Add please word "correspondingly" (or equivalent) in english text. It is _very_ important for some solutions of this problem.

Also word "points" would be great because there is no such thing as "coordinates of the bounds".

In problem statement:
"The arc of fire doesn’t exceed 180 degrees."
"Сектор обстрела не превышает 180 градусов."

"doesn't excees" is <=, not <. But test set doesn't contain test with arc of fire exactly 180 degrees.

Please add test where the arc of fire is 180 degrees. Only solutions that use vectors (and assume that first bound of arc is right and the second is left) will survive it. Solutions that use lines (or do not distinguish left and right bounds) will get wa.

Or if you do not want many authors get wa, change the statement: "The arc of fire is strictly less than 180 degrees." "Сектор обстрела строго меньше 180 градусов."

Edited by author 11.01.2009 14:29

"расстояние от домика боба"
->
"расстояние от домика Боба"

and please synchronize

пулемет Какашникова
Kalashnikov machine gun

(3rd letter :-))

is such a test legal:

5 1 1 1 1
2
1 1
-1 -1

if yes, then what shoud be the answer?..

Here is my code :
Const fi='input.txt';
      fo='output.txt';
Var Range,a1,b1,a2,b2,x,y,x1,y1,x2,y2:real;
    n,i,j:integer;
    f,g:text;
{------------------------------------------------------------------------}
Begin
  Assign(f,fi); Reset(f);
  Assign(g,fo); Rewrite(g);

  Readln(f,Range,x1,y1,x2,y2);
  a1:=y1; a2:=y2; b1:=x1*(-1); b2:=x2*(-1);
  Readln(f,n);
  for i:=1 to n do
    Begin
      Readln(f,x,y);
      if (sqrt(x*x + y*y)<=Range) then
      if (x1<>x2) or (y1<>y2) then
        begin
        if ((x*a1+y*b1)*(x2*a1+y2*b1)>=0) and
                 ((x*a2+y*b2)*(x1*a2+y1*b2)>=0) then
          Begin
            Writeln(g,'YES');
            Continue;
          End;
        End
      else if (x1=x2) and (y1=y2) then
        if (x*a1+y*b1)=0 then
          Begin
            Writeln(g,'YES');
            Continue;
          ENd;

      Writeln(g,'NO');
    End;

  Close(f);
  Close(g);
End.

here's in pascal:

my c code:

Edited by author 21.04.2008 03:06

Can anyone please say, what is this test?
My program completed all tests from neighbour topics successfully...

UPD: rewrote, got AC.

Edited by author 05.04.2008 23:36

Give me 10 test please

help!

In test №8 {x1,y1} and {x2,y2} sameway vectors.
PS
I hope, It'll help someone.=)
PPS
Sorry for my english.