LeetCode(Combination Sum)

Combination Sum
深搜：

class Solution {
public:
    vector<vector<int> > combinationSum(vector<int> &candidates, int target) {
        sort(candidates.begin(),candidates.end());
        vector<vector<int> > result;
        vector<int> path;
        dfs(candidates,result,path,0,target);
        return result;
    }
    void dfs(vector<int> &candidates,vector<vector<int> > &result,vector<int> &path,int start,int gap)
    {
        if(gap==0)
        {
            result.push_back(path);
            return;
        }
        for(int i=start;i<candidates.size();++i)
        {
            if(candidates[i]>gap)return;
            path.push_back(candidates[i]);
            dfs(candidates,result,path,i,gap-candidates[i]);
            path.pop_back();
        }
    }
};

Combination Sum II
深搜：

class Solution {
public:
    vector<vector<int> > combinationSum2(vector<int> &num, int target) {
        sort(num.begin(),num.end());
        vector<vector<int> > result;
        vector<int> path;
        dfs(num,result,path,0,target);
        return result;
    }
    void dfs(vector<int> &num,vector<vector<int> > &result,vector<int> &path,int start,int gap)
    {
        if(gap==0)
        {
            result.push_back(path);
            return;
        }
        for(int i=start;i<num.size();++i)
        {
            if(i>start&&num[i]==num[i-1])continue;
            if(num[i]>gap)return;
            path.push_back(num[i]);
            dfs(num,result,path,i+1,gap-num[i]);
            path.pop_back();
        }
    }
};