LeetCode Solutions : Combination Sum I & II

标签：leetcode   java   algorithms   datastructure   np   

Combination Sum 

public class Solution {
    public ArrayList<ArrayList<Integer>> combinationSum(int[] candidates, int target) {
        ArrayList<ArrayList<Integer>> results=new ArrayList<ArrayList<Integer>>();
		if(candidates==null)
			return results;
		Arrays.sort(candidates);
		helper(candidates,0,target,results,new ArrayList<Integer>());
		return results;
    }
	private void helper(int[] candidates,int start,int target,ArrayList<ArrayList<Integer>> results,ArrayList<Integer> temp){
		if(target==0){
			results.add(new ArrayList<Integer>(temp));
			return;
		}
		for(int i=start;i<candidates.length;i++){
			if(candidates[i]<=target){
				temp.add(candidates[i]);
				helper(candidates,i,target-candidates[i],results,temp);
				temp.remove(temp.size()-1);
			}
		}
	}
}

Combination Sum II 

public class Solution {
    public ArrayList<ArrayList<Integer>> combinationSum2(int[] num, int target) {
        ArrayList<ArrayList<Integer>> results=new ArrayList<ArrayList<Integer>>();
		if(num==null)
			return results;
		Arrays.sort(num);
		helper(num,0,target,results,new ArrayList<Integer>());
		return results;
    }
	private void helper(int[] candidates,int start,int target, ArrayList<ArrayList<Integer>> results,ArrayList<Integer> temp){
		if(target==0){
			results.add(new ArrayList<Integer>(temp));
			return;
		}
		for(int i=start;i<candidates.length;i++){
			if(i>start&&candidates[i]==candidates[i-1])
				continue;
			if(candidates[i]<=target){
				temp.add(candidates[i]);
				helper(candidates,i+1,target-candidates[i],results,temp);
				temp.remove(temp.size()-1);		
			}			
		}		
	}
}

LeetCode Solutions : Combination Sum I & II

标签：leetcode   java   algorithms   datastructure   np   

原文地址：http://blog.csdn.net/lviiii/article/details/39008797