Detect Squares LeetCode solution in C++

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class DetectSquares {
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 public:
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  vector<unordered_map<int, int>> x_axis;
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  DetectSquares() {
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    x_axis = vector<unordered_map<int, int>>(1005);
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  }
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  void add(vector<int> point) {
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    int x = point[0];
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    int y = point[1];
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    x_axis[x][y]++;
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  }
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  int count(vector<int> point) {
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    int x = point[0], y = point[1];
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    int res = 0;
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    for (auto &it : x_axis[x]) { // For all points lying on x_axis with value
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                                 // x_coordinate = x
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      int y_coord = it.first;
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      int countOcc = it.second;
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      if (y == y_coord) continue;
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      int sideLength = abs(y_coord - y);
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      // counting for p3' and p4'
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      if (x + sideLength <= 1000) // x_coordinate should be within range [0, 1000]
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      {
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        int newX = x + sideLength;
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        res += x_axis[x][y_coord] * x_axis[newX][y_coord] * x_axis[newX][y];
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      }
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      // counting for p3'' and p4''
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      if (x - sideLength >= 0) // x_coordinate should be within range [0, 1000]
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      {
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        int newX = x - sideLength;
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        res += x_axis[x][y_coord] * x_axis[newX][y_coord] * x_axis[newX][y];
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      }
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    }
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    return res;
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  }
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};