CareerCup

Which one is faster and why?
1. Array
2. Link List.
If we just want to iterate in for loop and print it.

You are given a dictionary, in the form of a file that contains one word per line. E.g.,
abacus
deltoid
gaff
giraffe
microphone
reef
qar
You are also given a collection of letters. E.g., {a, e, f, f, g, i, r, q}.
The task is to find the longest word in the dictionary that can be spelled with the collection of
letters. For example, the correct answer for the example values above is “giraffe”. (Note that
“reef” is not a possible answer, because the set of letters contains only one “e”.)

Following is an interview question asked by 'Amazon' to me. I still haven't come up with a optimized solution.

Problem Statement:
Given an unsorted array of integers n. Return 'true' if the addition of any integers from that array matches with the target value else return false.

Note:

1)'n' could be 1000 or 10,000.
2) Target value could be 'negative'
Test Condition:

i/p:- Array A[]= {-5,6,7,1,0,12,5,-6,100}
Target = 13
o/p:- TRUE

As, 6+7=13.
If we try to do it linearly or normally it will take O(2^n) time complexity.
So I am looking for any method or algorithm which will optimized this problem more.