leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
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2080.cpp (535B)

      1 class RangeFreqQuery {
      2     unordered_map<int, vector<int>> um;
      3 
      4   public:
      5     RangeFreqQuery(const vector<int> &arr) {
      6         for (int i = 0; i < size(arr); i++) {
      7             um[arr[i]].push_back(i);
      8         };
      9     }
     10 
     11     int query(int left, int right, int value) const {
     12         const auto it = um.find(value);
     13 
     14         static const vector<int> dummy;
     15         const auto &vec = it != end(um) ? it->second : dummy;
     16 
     17         return distance(lower_bound(begin(vec), end(vec), left), upper_bound(begin(vec), end(vec), right));
     18     }
     19 };