Brick Wall LeetCode solution in Java

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class Solution {
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  public int leastBricks(List<List<Integer>> wall) {
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    HashMap<Integer, Integer> edge_frequency =
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        new HashMap<>(); // HashMap to store the number of common edges among the rows
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    int max_frequency = 0; // Variable to store the frequency of most occuring edge
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    for (int row = 0; row < wall.size(); row++) // Iterating through each row
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    {
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      int edge_postion = 0; // Variable to store different edge postion
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      for (int brick_no = 0;
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          brick_no < wall.get(row).size() - 1;
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          brick_no++) // Iterating through each brick inside a row
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      {
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        int current_brick_length = wall.get(row).get(brick_no); // Length of the current brick
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        edge_postion =
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            edge_postion
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                + current_brick_length; // Next Edge Position = Previous Edge Position + Current
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        // Brick's Length
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        edge_frequency.put(
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            edge_postion,
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            edge_frequency.getOrDefault(edge_postion, 0)
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                + 1); // Incrementing the Frequency of just calculated Edge Postion
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        max_frequency =
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            Math.max(
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                edge_frequency.get(edge_postion),
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                max_frequency); // Comparing the "Frequency of just calculated Edge Postion" with
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        // "Max Frequency seen till now" & storing whichever is greater.
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      }
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    }
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    return wall.size()
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        - max_frequency; // returning (Number of Bricks Crossed by Line) i.e. (Number of Rows in
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    // Wall - Frequency of Most Occuring Edge)
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  }
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}