Combination Sum II

Combination Sum II

Problem:

Given A collection of candidate numbers (C) and a target number (T), find all unique combinations in c where the candidate numbers sums to T.

Each number in C is used once in the combination.

Note:

• All numbers (including target) would be positive integers.
• Elements in a combination (a1, a 2, ..., aK) must is in non-descending order. (ie, a1≤ a2≤ ... ≤ ak).
• The solution set must not contain duplicate combinations.

Ideas:

Common backtracking problems

My Code:

 Public classSolution { PublicList<list<integer>> combinationSum2 (int[] num,inttarget) {        if(num = =NULL|| Num.length = = 0)returnrst; List<Integer> list =NewArraylist<integer>();        Arrays.sort (num); Helper (list, num, target,0, 0); returnrst; }    PrivateList<list<integer>> rst =NewArraylist<list<integer>>();  Public voidHelper (list<integer> List,int[] candidates,intTargetintSumintstart) {        if(Sum > Target)return; if(Sum = =target) {            if(!rst.contains (list)) Rst.add (NewArrayList (list)); return; }         for(inti = start; i < candidates.length; i++) {List.add (candidates[i]); Helper (list, candidates, target, sum+ Candidates[i], i + 1); List.remove (List.size ()+ W); }    }}

View Code

Combination Sum II