347.前 K 个高频元素

🉐查找 and 哈希表

class Solution {
public:
    vector<int> topKFrequent(vector<int>& nums, int k) {
        map<int, int> count;
        for(auto x :nums) {
            count[x] += 1;
        }
        using value_t = pair<int, int>;
        vector<value_t> container(count.begin(), count.end());
         auto comp = [](const value_t &v1, const value_t &v2) {return v1.second < v2.second;};
        make_heap(container.begin(), container.end(), comp);
        vector<int> result;
        for (int i = 0; i < k; ++i) {
            result.push_back(container.begin()->first);
            pop_heap(container.begin(), container.end() - i, comp);
        }
        return result;
    }
};

Accepted

21/21 cases passed (24 ms)

Your runtime beats 62.88 % of cpp submissions

Your memory usage beats 9.89 % of cpp submissions (11.7 MB)