Largest Submatrix With Rearrangements LeetCode solution in C++

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#pragma GCC optimize("O3")
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class Solution {
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 public:
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  int largestSubmatrix(vector<vector<int>> &matrix) {
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    int m = matrix.size(), n = matrix[0].size();
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    int area = count(matrix[0].begin(), matrix[0].end(), 1);
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    for (int i = 1; i < m; i++) {
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#pragma unroll
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      for (int j = 0; j < n; j++) {
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        if (matrix[i][j] != 0) matrix[i][j] += matrix[i - 1][j];
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      }
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      auto row = matrix[i];
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      sort(row.begin(), row.end());
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#pragma unroll
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      for (int i = 0; i < n; i++) area = max(area, row[i] * (n - 1 - i + 1));
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    }
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    return area;
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  }
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};
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auto init = []() {
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  ios::sync_with_stdio(0);
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  cin.tie(0);
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  cout.tie(0);
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  return 'c';
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}();