Combination Sum

Given a set of candidate numbers (C) and a target number (T),
find all unique combinations in C where the candidate numbers sums to T.
The same repeated number may be chosen from C unlimited number of times.
Note
All numbers (including target) will be positive integers.
Elements in a combination (a1, a2, ... , ak) must be in non-descending order. (ie, a1 <= a2 <= ... <= ak).
The solution set must not contain duplicate combinations.
Example
Given candidate set 2,3,6,7 and target 7,
A solution set is:
[7]
[2, 2, 3]

Login to see Answer and Coaching Session More interview questions