使用Min Heap实现Top N Elements查找

std::vector<int> TopN_MinHeap(std::vector<int> &nums, int n)

{

     std::priority_queue<int, std::vector<int>, std::greater<int>> q;

     for (int i = 0; i < n; i++)

          q.push(nums[i]);

     int sizeOfNums = nums.size();

     for (int i = n; i < sizeOfNums; i++)

     {

          q.push(nums[i]);

          q.pop();

     }

     std::vector<int> result;

     while (q.size() > 0) {

            result.push_back(q.top());

            q.pop();

     }

     return result;

}