1774. Closest Dessert Cost

周賽復盤, 我選用dfs, 並且用一張表紀錄出現過的次數, 每用一次就-1

比較要注意的是 base要也去計算最靠近的result, 因為我們有一種可能是可以不加topping

class Solution {
public:
    void dfs(int target,  unordered_map<int, int> tc_m, int cur, int &res){
        for(auto &t :tc_m){
            if(t.second <= 0) continue;
            if(cur + t.first > target){
                res = abs(cur + t.first  - target) < abs(res-target)?cur + t.first:res;
                continue;
            }
            if(cur + t.first  == target){
                res = cur + t.first;
                return;
            }
            res = abs(cur + t.first  - target) < abs(res-target)?cur + t.first:res;
            t.second--;
            dfs(target, tc_m, cur + t.first, res);
        }
    }
    int closestCost(vector<int>& bcs, vector<int>& tc, int target) {
        int res = INT_MAX;
        unordered_map<int, int> tc_m;
        for(auto t: tc){
            tc_m[t] = 2;
        }
        for(auto bc: bcs){
            int t = target - bc;
            res = abs(bc - target) < abs(res-target)?bc:res;
            dfs(target, tc_m, bc, res);
        }
        return res;
    }
};