Discussion @ 1793. Tray 2 @ Timus Online Judge

UstinovG`~ WA31 // Problem 1793. Tray 2 30 Jun 2020 13:30

Check What is the test #19? Please give me a test so that I can check and correct it. Thanks ! [3] // Problem 1793. Tray 2 22 Aug 2011 13:03

Juve45 Hint for WA 16 [1] // Problem 1793. Tray 2 9 Sep 2017 17:07

bsu.mmf.team WA25 [16] // Problem 1793. Tray 2 16 Oct 2010 16:10

people! who has any ideas?

Stav_team Re: WA25 // Problem 1793. Tray 2 16 Oct 2010 16:32

What about test 13? What is test ??!?!?!

CABALA Re: WA25 [1] // Problem 1793. Tray 2 16 Oct 2010 16:40

Check if the plate fits in the tray

Stav_team Re: WA25 // Problem 1793. Tray 2 16 Oct 2010 17:33

I check plate if in tray but WA 13 !!!

Oleg Strekalovsky [Vologda SPU] Re: WA25 [8] // Problem 1793. Tray 2 17 Oct 2010 02:32

bsu.mmf.team wrote 16 October 2010 16:10

people! who has any ideas?

Do you found test or reason for WA 25?

Ibragim Atadjanov (Tashkent U of IT) Re: WA25 [5] // Problem 1793. Tray 2 17 Oct 2010 03:15

I also had that problem but when I checked if big plate is placed in tray (2 * r > b here r is the radius of cone at the height d (d < h) and b is small side of tray).
But now I have wa on test31

good luck

Oleg Strekalovsky [Vologda SPU] Re: WA25 [4] // Problem 1793. Tray 2 17 Oct 2010 03:28

Ibragim Atadjanov (Tashkent U of IT) wrote 17 October 2010 03:15

I also had that problem but when I checked if big plate is placed in tray (2 * r > b here r is the radius of cone at the height d (d < h) and b is small side of tray).
But now I have wa on test31

good luck

Thanks. I can add, that we must check:
0 <= x + r && x + r <= w && 0 <= x - r && x - r <= w &&
0 <= y + r && y + r <= h && 0 <= y - r && y - r <= h;
for both plate x,y - coordinates of plate center's, r - minimal radius of plate, w,h - max(a,b), min(a,b)

Test:
2 10 1
1 3
1 3
2
Ans:
NO

Edited by author 17.10.2010 03:31

Ibragim Atadjanov (Tashkent U of IT) Re: WA25 // Problem 1793. Tray 2 17 Oct 2010 03:39

thanks your test helped me a lot. Thanks again

melkiy Re: WA25 [2] // Problem 1793. Tray 2 18 Oct 2010 00:13

I've read all the advice: my code meets all of them. Any other suggestions on WA25? Maybe someone is ready to look at my code? My e-mail is in my info. Thanks for any help.

MAK Re: WA25 [1] // Problem 1793. Tray 2 18 Oct 2010 15:32

I made a stupid mistake while reading the input data. First I read bottom sides and then top sides. Surprisingly, this solution bring me to WA25 and half-an-hour debugging.

melkiy Re: WA25 // Problem 1793. Tray 2 18 Oct 2010 19:06

It turned out I had read data in the same wrong manner and also got WA25! MAK, your advice was the most useful in this discussion ))

Ibragim Atadjanov (Tashkent U of IT) Re: WA32 please help // Problem 1793. Tray 2 17 Oct 2010 03:28

Edited by author 17.10.2010 03:39

bsu.mmf.team Re: WA25 // Problem 1793. Tray 2 17 Oct 2010 13:37

Yes! It was a very stupid mistake! I checked if radius of plates on the height d is not greater than a and not grater than b. But I should check their diameter instead it! This fact costed me 13 fail submissions...

D-305 Re: WA25 [2] // Problem 1793. Tray 2 19 Oct 2010 23:06

Try this test:
9 15 1
1 2
1 5
1

Answer is NO.

alp Re: WA25 [1] // Problem 1793. Tray 2 26 Feb 2011 00:45

Why NO?
First (d=2)koord: 2 2
Second (d=5) koord: 4 10

I think YES, but WA 25...

alp Re: WA25 // Problem 1793. Tray 2 26 Feb 2011 18:28

i understood...

Dmitri Belous Re: WA25 // Problem 1793. Tray 2 9 Oct 2017 20:25

This test helped me on WA25:
20 28 1
1 2
11 12
1
Answer: NO.

esbybb java AC code // Problem 1793. Tray 2 5 Oct 2015 01:02

Otrebus Hint // Problem 1793. Tray 2 30 May 2015 14:11

Zachary wa 28 [1] // Problem 1793. Tray 2 13 Mar 2012 15:17

ChocoS Question about the input [1] // Problem 1793. Tray 2 30 Jul 2011 17:39

Hrayr Wa#43 The code is here. [1] // Problem 1793. Tray 2 18 Jun 2011 16:09

Anton Chaplygin [Kungur] [Psych Up club] WA 15 [1] // Problem 1793. Tray 2 11 Aug 2012 20:58

Anatoly bad description of the problem [3] // Problem 1793. Tray 2 23 Jan 2012 04:00

Try_to_try I spent too much time on this problem. But still WA #28. Help me!! [1] // Problem 1793. Tray 2 24 Aug 2011 18:19

Can anyone tell me my mistake. Here is my code. Thanks
#include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include <deque>
#include <queue>
#include <set>
#include <map>
#include <algorithm>
#include <functional>
#include <utility>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <cstdio>
#include <cstring>
//#include <conio.h>

using namespace std;

#define oo 1000000000
#define fi first
#define se second
#define sqr(a) ((a)*(a))
#define FR(i,n) for (int i = 0; i < (n); i++)
#define DN(i,a) for(int i = (a)-1; i >= 0; i--)
#define FOR(i,a,b) for (int i = (a); i <= (b); i++)
#define DOWN(i,a,b) for(int i = (a); i >= (b); i--)
#define FORV(i,a) for(typeof(a.begin()) i = a.begin(); i != a.end(); i++)

typedef pair<int, int> PII;
typedef vector<int> VI;

double kc(double x1, double y1, double x2, double y2) {
    return sqrt(sqr(x1 - x2) + sqr(y1 - y2));
}

int main () {
    double a, b, d, r11, r12, r21, r22, h;
    cin >> a >> b >> d;
    cin >> r11 >> r12 >> r21 >> r22 >> h;
    if (2 * max(r21, r11) > min(a, b)) {
        cout << "NO" << endl;
        return 0;
    }
    double x1 = r11, y1 = r11;
    double x2 = a - r21, y2 = b - r21;
    if (kc(x1, y1, x2, y2) < r11 + r21) {
        cout << "NO" << endl;
        return 0;
    }
    if (d >= h) {
        if (2 * max(r12, r22) > min(a, b)) {
            cout << "NO" << endl;
            return 0;
        }
        double x1 = r12, y1 = r12;
        double x2 = a - r22, y2 = b - r22;
        if (kc(x1, y1, x2, y2) < r12 + r22) {
            cout << "NO" << endl;
            return 0;
        }
    }
    if (d < h) {
        double r1m = d * (r12 - r11) / h + r11;
        double r2m = d * (r22 - r21) / h + r21;
        if (2 * max(r1m, r2m) > min(a, b)) {
            cout << "NO" << endl;
            return 0;
        }
        double x1 = r1m, y1 = r1m;
        double x2 = a - r2m, y2 = b - r2m;
        if (kc(x1, y1, x2, y2) < r1m + r2m) {
            cout << "NO" << endl;
            return 0;
        }
    }
    cout << "YES" << endl;
    return 0;
}

watashi Re: I spent too much time on this problem. But still WA #28. Help me!! // Problem 1793. Tray 2 12 Jan 2012 19:18

You're using sqrt which loses precision.
you should use int64.

Conserj WA21 with code [1] // Problem 1793. Tray 2 23 Dec 2011 04:32

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Тарелки2
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] parampidn = Console.ReadLine().Split(' ');
            int a = int.Parse(parampidn[0]);
            int b = int.Parse(parampidn[1]);
            int d = int.Parse(parampidn[2]);
            string[] muska1 = Console.ReadLine().Split(' ');
            int r1 = int.Parse(muska1[0]);
            int r2 = int.Parse(muska1[1]);
            int minradmuska1 = 0, maxradmuska1 = 0;
            if (r1 > r2)
            {
                maxradmuska1=r1;
            }
            else r2 = maxradmuska1;
            if (r2 > r1)
            {
                minradmuska1 = r1;
            }
            else minradmuska1 = r2;
            string[] muska2 = Console.ReadLine().Split(' ');
            int R1 = int.Parse(muska2[0]);
            int R2 = int.Parse(muska2[1]);
            int minradmuska2=0, maxradmuska2=0;
            if (R1 > R2)
            {
                maxradmuska2 = R1;
            }
            else maxradmuska2 = R2;
            if (R2 > R1)
            {
                minradmuska2 = R1;
            }
            else minradmuska2 = R2;
            int h = int.Parse(Console.ReadLine());
            int minst=0, maxst=0, maxradvel12;
            if (maxradmuska1>maxradmuska2)
            {
                maxradvel12=maxradmuska1;
            }
            else maxradvel12=maxradmuska2;
            if (a>b)
            {
                minst=b;
            }
            else minst =a;
            if (a>b)
            {
                maxst=a;
            }
            else maxst=b;
            if (((2*maxradmuska1+2*maxradmuska2)<=maxst)&&(2*maxradvel12<=minst)&&(2*maxradmuska1+2*maxradmuska2<=
                Math.Sqrt((double)a*a+(double)b*b)))
            {
                Console.WriteLine("YES");
            }
            else
            {
                Console.WriteLine("NO");
            }
        }
    }
}

Conserj Re: WA21 with code // Problem 1793. Tray 2 23 Dec 2011 04:33

что не так-то?

Uzbek boy WA #13 [1] // Problem 1793. Tray 2 12 Oct 2011 14:34

nskoryukina Fail solution is accepted [1] // Problem 1793. Tray 2 1 Nov 2011 22:43

Ozod WA 19 HELP ME // Problem 1793. Tray 2 12 Sep 2011 08:51

198808xc Notes to authors of this problem. [4] // Problem 1793. Tray 2 31 Aug 2011 21:45

In fact, it cost me 4 submissions to get accepted. However, I still think that this is a problem with simple geometry. However, some confusion in the problem statement rather made a big trouble for me.

The problem statement said that the plates had the shape of truncated cones. However, it still remains a problem, that which bottom of the truncated cone is larger. By the common sense, the upper bottom of the cone should be larger, and it is indeed so in the testdata (I have submitted a checker for this), but the fact does not appear in the statements.
PS: even if the lower bottom is larger, my program could still give the correct results.

Secondly, the height of the tray need NOT be larger than (or equal with) the height of the cones. If the height of tray is smaller, the plates could still fit in the tray, and in this situation, some part of the plates could even be outside the tray. So important the condition is, it doesn't appear in the problem statements at all! I could not understand this.

And, at last, I want to give the last hint to all authors: try to solve this problem by 64-bit integers. Floating point numbers might bring in errors, which you don't want to see.

Sandro (USU) Re: Notes to authors of this problem. [1] // Problem 1793. Tray 2 31 Aug 2011 22:12

Oops! Of course, the radius of plate's edge is greater than the radius of plate's bottom.
I have fixed the problem statement.

198808xc Re: Notes to authors of this problem. // Problem 1793. Tray 2 31 Aug 2011 22:55

Well, I think that correcting the second confusion could be more important.

Or, is this an intentional trap of this problem?

IgorKoval(from Pskov) Re: Notes to authors of this problem. [1] // Problem 1793. Tray 2 1 Sep 2011 03:03

It's good idea to use 64-bit fractional arithmetic.

#include <iostream>
#include <algorithm>
using namespace std;

__int64 gcd( __int64 a, __int64 b ) {
    return b? gcd( b, a%b ) : a ;
}

class drobT {
    public :
        __int64 u, d;
        drobT()
        {
            u = 0;
            d = 1;
        }
        friend drobT socr ( drobT a ) {
            __int64 div, x, y;
            x = (a.u>=0)? a.u : -1*a.u;
            y = (a.d>=0)? a.d : -1*a.d;
            div = gcd( max(x,y), min(x,y) );
            a.u /= div;
            a.d /= div;
            return a;
        }
        friend drobT operator + ( const drobT& a, const drobT& b )
        {
            drobT c;
            c.u = a.u * b.d + b.u * a.d;
            c.d = a.d * b.d;
            return socr(c);
        }
        friend drobT operator - ( const drobT& a, const drobT& b )
        {
            drobT c;
            c.u = a.u * b.d - b.u * a.d;
            c.d = a.d * b.d;
            return socr(c);
        }
        friend drobT operator * ( const drobT& a, const drobT& b )
        {
            drobT c;
            c.u = a.u * b.u;
            c.d = a.d * b.d;
            return socr(c);
        }
        friend drobT operator * ( const __int64& a, const drobT& b )
        {
            drobT c;
            c.u = a * b.u;
            c.d = b.d;
            return socr(c);
        }
        friend drobT operator / ( const drobT& a, const drobT& b )
        {
            drobT c = b;
            if( c.u < 0 ) {
                c.u = -c.u;
                c.d = -c.d;
            }
            swap( c.d, c.u );
            return socr(c * a);
        }
        friend bool operator <= ( drobT a, drobT b ) { return a.u*b.d <= a.d*b.u;}
        friend bool operator <= ( const __int64 a, drobT b ) { return a*b.d <= b.u;}
        friend bool operator < ( drobT a, drobT b ) { return a.u*b.d < a.d*b.u; }
        friend bool operator < ( const __int64 num, drobT b ) { return num*b.d < b.u; }
        friend drobT pow2( const drobT& a ){ return a*a; }
};
//input
istream& operator >> ( istream& cin, drobT& dr ) {
    cin >> dr.u;
    dr.d = 1;
    return cin;
}

/*
secret code)
*/

198808xc Re: Notes to authors of this problem. // Problem 1793. Tray 2 1 Sep 2011 19:42

Wow, it's a good template for double-precision calculations.
However, this problem could be solved with single-precision __int64 numbers.

Newbies WA 28 [5] // Problem 1793. Tray 2 11 Nov 2010 18:49

Check Any Ideas how to solve it? [1] // Problem 1793. Tray 2 22 Aug 2011 02:18

TheDreamCatcher WA31 // Problem 1793. Tray 2 4 Dec 2010 09:50

Discussion of Problem 1793. Tray 2