[leetcode刷题系列]Combination Sum II

- - 继续暴力把

class Solution {    void dfs(vector<pair<int, int>> &vp, int p, int target, vector<int> & stk,        vector<vector<int> > & ans){            if(target == 0){                ans.push_back(stk);                return ;            }            if(p >= vp.size())                return ;            // not use            dfs(vp, p + 1, target, stk, ans);            // use            int i = 1;            for(; i <= vp[p].second && i * vp[p].first <= target; ++ i){                stk.push_back(vp[p].first);                dfs(vp, p + 1, target - i * vp[p].first, stk, ans);            }            while(--i > 0)                stk.pop_back();        }public:    vector<vector<int> > combinationSum2(vector<int> &num, int target) {        // Start typing your C/C++ solution below        // DO NOT write int main() function        map<int, int> hash;        for(int i = 0; i < num.size(); ++ i)            hash[num[i]] ++ ;        vector<pair<int, int> > vp;        for(map<int, int> :: iterator it = hash.begin();            it != hash.end(); ++ it)            vp.push_back(make_pair(it->first, it->second));                vector<vector<int> > ans;        vector<int> stk;        dfs(vp, 0, target, stk, ans);        return ans;    }};