[algogeeks] Re: Fastest way to find arbitary element in linked list?

2005-12-02 Thread pramod
Use two pointers, one 5 elements ahead of the other. Now move both pointers ahead together by one element until the first one hits the end, the second pointer will point to the fifth element from the last.

[algogeeks] Re: Design an algorithm

2005-12-02 Thread pramod
In my algo, this O(N) space restriction is not violated. Each computer uses O(N) space only. But overall, all the N computers use O(N^2) space.

[algogeeks] Re: Finding duplicate

2005-12-02 Thread pramod
I agree with Dhyanesh. This "counting" sort routine prescribed by Adak fails when the numbers can be random. Dhyanesh, I searched for "element uniqueness" and that problem is more generic. It says to find if all the numbers are unique. But in my problem it is known that exactly one number is dupli

[algogeeks] Re: Finding duplicate

2005-12-02 Thread Dhyanesh
Btw how would your algo work if the numbers were { 1, 4, 5, 10^100 , 45, 5 } I dont believe you can create an array of size 10^100. This problem cannot be solved in better than O(nlgn). -Dhyanesh On 12/2/05, adak <[EMAIL PROTECTED]> wrote: Hi pramod,I'm not sure what the "right" name for th

[algogeeks] Re: Efficient data structure to store sorted timestamped data

2005-12-02 Thread adak
Would it be possible to do your calculations on the data as your worked your way through the data using an array of structs? Even if you only could load 5,000 or 10,000 structs at a time into the array, that could provide a fast way to do the work, and then just reload the array with the next 5,0

[algogeeks] Re: Finding duplicate

2005-12-02 Thread adak
Hi pramod, I'm not sure what the "right" name for this is, if anybody knows I hope they jump in with that info for us. In the original problem, the set of numbers contained just ONE duplicate value. So let's say the set is { 3, 9, 6, 4, 4} The array that is built up by the loop would then be ha

[algogeeks] Re: Fastest way to find arbitary element in linked list?

2005-12-02 Thread Rave Hanker
Well,     Even if its O(n) , one way to reduce the steps required for finding the length of the list(which is required here) is two use the Hare and Tortoise method where there are two pointers (Hare and the Tortoise) . The Hare moves two steps for each step the tortoise takes. The tortoise would t

[algogeeks] Re: 100 programmers

2005-12-02 Thread Yunzhong
Hi pramod, Just read your method. The only problem is this: "Ultimately we'll be left with one person in T." I think this cannot be ensured. You may be left with a few people who know each other.

[algogeeks] Re: Design an algorithm

2005-12-02 Thread Abhi
one of the restriction is that a computer can only hold O(N) integers.

[algogeeks] Re: Fastest way to find arbitary element in linked list?

2005-12-02 Thread Abhi
In a link list the search is always going to be O(n) unless you customize/modify it. -Abhishikt

[algogeeks] Re: Efficient data structure to store sorted timestamped data

2005-12-02 Thread Gene
If you want to use the fact that the data are sorted, you can just read the file once in order to build an array of integers that are the character offsets of the start of each line. (If all the lines are the same length, you don't even need to do this!) Then use file seek (direct access) and bin

[algogeeks] Re: Efficient data structure to store sorted timestamped data

2005-12-02 Thread Deepak Shah
you will need to implement data structure = hash table + linked list   In Java there is one available called LinkedHashSet (assuming that your timestamps are all different, otherwise you can't use set).   Hash table and linked list implementation of the Set interface, with predictable iteration ord

[algogeeks] Re: Efficient data structure to store sorted timestamped data

2005-12-02 Thread Jay
I need to get all data between two timestamps. So suppose I use hashtable, I can easily find the starting timestamp. Then how do I look for all timestamps between the starting timestamp and ending timestamp in the hashtable.

[algogeeks] Fastest way to find arbitary element in linked list?

2005-12-02 Thread Deepak Shah
Can someone answer to this :   http://www.algogeeks.com/fastest_way_to_find_arbitary_element_in_linked_list

[algogeeks] Re: Efficient data structure to store sorted timestamped data

2005-12-02 Thread Deepak Shah
  but I am not making any use of the fact that the data is sorted   This sounds like unnecessary consideration. Once you have data in hashtable, based on hashtable implementation you can even have sorted data available through iterator.       On 12/2/05, Jay <[EMAIL PROTECTED]> wrote: I have to rea

[algogeeks] Efficient data structure to store sorted timestamped data

2005-12-02 Thread Jay
I have to read a large file where every line is timestamped and the file is sorted by timestamp. I need to store all that data in some good data structure so that later on I can easily do calculations on data between two timestamps meaning I will have to search based on date-time later. If I u

[algogeeks] Re: Finding duplicate

2005-12-02 Thread Dhyanesh
Hi If the numbers are arbitrary then you can not do better than O ( n log (n ) ) ... this is a proven lower bound.  Google for "Element Uniqueness"  and you will find links to these proofs. -DhyaneshOn 12/2/05, pramod <[EMAIL PROTECTED]> wrote: I am sorry I did not get your solution.So if the giv

[algogeeks] Re: decimal to binary conversion

2005-12-02 Thread Roberto Abreu
 / and Stacks On 12/2/05, vive <[EMAIL PROTECTED]> wrote: hi i have to do followingdecimal to binary conversioncan antone help me please

[algogeeks] decimal to binary conversion

2005-12-02 Thread vive
hi i have to do following decimal to binary conversion can antone help me please

[algogeeks] Re: Finding duplicate

2005-12-02 Thread pramod
I am sorry I did not get your solution. So if the given array is say { 5, 1, 8, 100 } all are > 1, how will your algo work? Or you had counting sort in mind? for my problem, counting sort is ruled out.

[algogeeks] Re: Finding duplicate

2005-12-02 Thread adak
If it's possible for the array to encompass by subscript, the entire range of the numbers, then this is VERY fast. for each n, { array[n] += 1 if(array[n] > 1) /* you have found the duplicate n */ break; } I call this "doing a distribution count", but I'm sure there's a better term