Обсуждение @ 1648. Яхты @ Timus Online Judge

Asyamov Igor What is a right algorithm to that problem? [15] // Задача 1648. Яхты 26 окт 2008 11:53

Tell me please!
Is it greedy???

Ivan Yes (-) // Задача 1648. Яхты 26 окт 2008 12:14

svr Re: What is a right algorithm to that problem? [12] // Задача 1648. Яхты 26 окт 2008 19:56

Greedy only? I think.
I don't solve else but think that next algo is right:
1. maximal production =d in all n periods;
2. Greedy approach :satisfy first demand as fully as possible;
3. If we have residue in last period equal to k
diminish by k residues in previous periods until it is possible
4. Sum final residues along all periods.

Edited by author 26.10.2008 20:52

Asyamov Igor Re: What is a right algorithm to that problem? [11] // Задача 1648. Яхты 26 окт 2008 20:37

My algo is the same as your! (but still wa 15) :-(

Vedernikoff Sergey (HSE: EconomicsForever!) Re: What is a right algorithm to that problem? // Задача 1648. Яхты 26 окт 2008 21:07

Use DP

svr Re: What is a right algorithm to that problem? [9] // Задача 1648. Яхты 26 окт 2008 21:43

You definitely need reading math eco theory
optimal store managing(Taha a.s.o.)
P.S.I also have WA14. First number of output I guarantee but
the second need more delicate algo.

Asyamov Igor Re: What is a right algorithm to that problem? [8] // Задача 1648. Яхты 26 окт 2008 21:47

may be your problem with the type of the second number(it should be __int64)???

Maxim Dvoynishnikov (Dnipropetrovsk SU) * [1] // Задача 1648. Яхты 27 окт 2008 01:32

I have WA49 with greedy and restroring.

double Re: * // Задача 1648. Яхты 27 окт 2008 06:17

use int64(long long) ,then you'll get AC.

svr Re: What is a right algorithm to that problem? [5] // Задача 1648. Яхты 27 окт 2008 09:21

Yuare right!
With __int 64 AC.
I didn'r recognized masked danger:100000*100000=10*1-e9.
All data seemed fitted in int type.

Edited by author 27.10.2008 09:21

Asyamov Igor Re: What is a right algorithm to that problem? [4] // Задача 1648. Яхты 27 окт 2008 18:02

Are you got AC with your algo or you had chaged it???

Asyamov Igor Re: What is a right algorithm to that problem? // Задача 1648. Яхты 27 окт 2008 18:16

Edited by author 28.10.2008 14:51

svr Re: What is a right algorithm to that problem? [2] // Задача 1648. Яхты 27 окт 2008 18:54

I considered stored values backward more attentievely
according with alg:
store[i-1]=max(store[i]+sell[i-1]-d,0)
store[n]:=0;
i=n..1
where sell[i-1] array of greedy selling on the first stage.

Asyamov Igor Re: What is a right algorithm to that problem? [1] // Задача 1648. Яхты 28 окт 2008 15:39

Accepted!!!!!!
this test help me find my bug...
in:
5 5
3 1 20 3 10
out: 25 10

and now,after accepted, could somebody, who solved this problem with DP, sent to me your solution?
my mail: asyamov@mail.ru

Edited by author 28.10.2008 16:18

lql1993 Re: What is a right algorithm to that problem? // Задача 1648. Яхты 2 дек 2008 16:30

I think greedy can work well.

Vit Demidenko Re: What is a right algorithm to that problem? // Задача 1648. Яхты 27 авг 2010 20:27

I don'n understand, how to solve this problem whith DP or greedy. I solve with RMQ.

Обсуждение задачи 1648. Яхты