LeetCode: Combination Sum II

改了挺多次，不过最后还是被我搞出来了^^, 用了map的技巧勉强过了large。

class Solution {
public:
    void dfs(vector<int> num, int target, int sum, vector<int> &save, map<vector<int>, int> &reti, int cur) {
        if (sum > target) return;
        if (sum == target) {
            reti.insert(pair<vector<int>, int>(save, 0));
            return;
        }
        for (int i = cur; i < num.size(); i++) {
            save.push_back(num[i]);
            dfs(num, target, sum+num[i], save, reti, i+1);
            save.pop_back();
        }
    }
    vector<vector<int> > combinationSum2(vector<int> &num, int target) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        vector<vector<int>> ret;
        map<vector<int>, int> reti;
        if (num.size() == 0) return ret;
        sort(num.begin(), num.end());
        vector<int> save;
        int sum = 0;
        int cur = 0;
        dfs(num, target, sum, save, reti, cur);
        for (map<vector<int>, int>::iterator it = reti.begin(); it != reti.end(); it++) {
            ret.push_back(it->first);
        }
        return ret;
    }
};

 C#

public class Solution {
    public List<List<int>> CombinationSum2(int[] candidates, int target) {
        Array.Sort(candidates);
        int sum = 0;
        List<List<int>> ans = new List<List<int>>();
        List<int> tmp = new List<int>();
        if (candidates.Length == 0) return ans;
        int dep = 0;
        dfs(candidates, target, sum, ref tmp, ref ans, dep);
        return ans;
    }
    void dfs(int[] candidates, int target, int sum, ref List<int> tmp, ref List<List<int>> ans, int dep)
    {
        if (sum > target) return;
        if (sum == target) {
            List<int> newTmp = new List<int>();
            for (int i = 0; i < tmp.Count; i++) newTmp.Add(tmp[i]);
            ans.Add(newTmp);
            return;
        }
        for (int i = dep; i < candidates.Length; i++) {
            if (i > dep && candidates[i] == candidates[i-1]) continue;
            tmp.Add(candidates[i]);
            dfs(candidates, target, sum + candidates[i], ref tmp, ref ans, i+1);
            tmp.RemoveAt(tmp.Count - 1);
        }
    }
}