Maximum Building Height LeetCode solution in Java

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class Solution {
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  public int maxBuilding(int n, int[][] restrictions) {
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    List<int[]> list = new ArrayList<>();
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    list.add(new int[] {1, 0});
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    for (int[] restriction : restrictions) {
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      list.add(restriction);
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    }
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    Collections.sort(list, new IDSorter());
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    if (list.get(list.size() - 1)[0] != n) {
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      list.add(new int[] {n, n - 1});
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    }
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    for (int i = 1; i < list.size(); i++) {
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      list.get(i)[1] =
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          Math.min(list.get(i)[1], list.get(i - 1)[1] + list.get(i)[0] - list.get(i - 1)[0]);
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    }
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    for (int i = list.size() - 2; i >= 0; i--) {
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      list.get(i)[1] =
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          Math.min(list.get(i)[1], list.get(i + 1)[1] + list.get(i + 1)[0] - list.get(i)[0]);
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    }
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    int result = 0;
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    for (int i = 1; i < list.size(); i++) {
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      int h1 = list.get(i - 1)[1]; // heigth of previous restriction
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      int h2 = list.get(i)[1]; // height of current restriction
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      int x = list.get(i - 1)[0]; // id of previous restriction
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      int y = list.get(i)[0]; // id of current restriction
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      result = Math.max(result, Math.max(h1, h2) + (y - x - Math.abs(h1 - h2)) / 2);
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    }
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    return result;
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  }
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  public class IDSorter implements Comparator<int[]> {
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    @Override
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    public int compare(int[] myself, int[] other) {
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      return myself[0] - other[0];
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    }
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  }
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}