Discussion @ 1002. Phone Numbers @ Timus Online Judge

Hikmat Ahmedov Greedy algorithm doesn't pass Test 3. Which algorithm to use ? [5] // Problem 1002. Phone Numbers 22 Aug 2012 22:02

Greedy algorithm doesn't pass Test 3. Which algorithm to use ?
Please don't say just DP+tree.
How do you buld a tree ?
Building a tree is not problem, we can build the tree using STACK but it gives TLE on test 5.
It takes too much time to build the whole tree.
In this promlem, order of the words is important, so I have no idea how to use DP.

Please, give some hints.
Thanks,

KNIGHT0X300 Re: Greedy algorithm doesn't pass Test 3. Which algorithm to use ? [2] // Problem 1002. Phone Numbers 26 Aug 2012 22:47

just DP Similar to Knapsack(I think) and need to store the previous element to recover the path in the end :)

Hikmat Ahmedov Re: Greedy algorithm doesn't pass Test 3. Which algorithm to use ? [1] // Problem 1002. Phone Numbers 31 Aug 2012 10:46

In Knapsack order is not important, but in this problem order is important.
How do you deal with order ?

Endoveg Re: Greedy algorithm doesn't pass Test 3. Which algorithm to use ? // Problem 1002. Phone Numbers 30 Jul 2013 00:57

KNIGHT0X300 is right. It is an example of DP problem.

Mohammad Samiul Islam Re: Greedy algorithm doesn't pass Test 3. Which algorithm to use ? // Problem 1002. Phone Numbers 19 Mar 2014 20:11

I got AC using Trie Tree and Knapsack DP.

dangminhhieu78 Re: Greedy algorithm doesn't pass Test 3. Which algorithm to use ? // Problem 1002. Phone Numbers 2 Jan 2015 08:37

use hash+dp

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