Re: [algogeeks] Suggested the Data Structure to implement the solution in O(1)

2013-01-09 Thread Karthikeyan V.B
Hi, Use hashing, but with perfect hashing which does all these operations in O(1). Refer to Introduction to Algorithms by CLRS to learn about perfect hashing. --

Re: [algogeeks] Re: sortin 2D array

2013-01-09 Thread Karthikeyan V.B
Merge pairs of rows until u get a single row, while merging remove the duplicates --

Re: [algogeeks] Re: Minimum sum of Array

2013-01-09 Thread Carl Barton
How is it a huge improvement? Your O(SN) is the same time as the dynamic programming solution for 0-1 knapsack isn't it? On 8 January 2013 14:44, Don dondod...@gmail.com wrote: Yes, that is true. However, trying to find the optimal partition is equivalent to the 0-1 knapsack problem, which is

[algogeeks] Re: Minimum sum of Array

2013-01-09 Thread Don
My solution is equivalent to using DP for the 0-1 knapsack, but the DP approach does not identify the partition, it only determines if it exists. In the same way, my solution does not determine which numbers to make negative. It only determines what the smallest possible sum is. The DP approach to

[algogeeks] Re: Suggested the Data Structure to implement the solution in O(1)

2013-01-09 Thread Don
I don't think that perfect hashing provides nthentry in constant time. You could store items in a vector indexed by the order in which they were inserted. Retrieving an item would be constant time, but what happens when you have thousands of items and you need to delete item 27? Now most of the

Re: [algogeeks] Re: Minimum sum of Array

2013-01-09 Thread prankur gupta
Hi, I have understood the solution, but here we are talking about knowing the path(elements in the subsets in this case). I saw we could use the back pointer technique, which I understood, but I'm not able to see how would I code this technique. Please try to explain me this thing. Thanks a lot