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class Solution {
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  // This method returns true if the given 4 points form a square, false otherwise
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  public boolean validSquare(int[] p1, int[] p2, int[] p3, int[] p4) {
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    // We use a set to store the distances between the points
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    Set<Integer> set = new HashSet();
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    // Calculate the distances between all pairs of points and add them to the set
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    set.add(distanceSquare(p1, p2));
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    set.add(distanceSquare(p1, p3));
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    set.add(distanceSquare(p1, p4));
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    set.add(distanceSquare(p2, p3));
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    set.add(distanceSquare(p2, p4));
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    set.add(distanceSquare(p3, p4));
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    // A square must have 4 equal sides, so the set must contain 2 different values (the lengths of
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    // the sides and the diagonals)
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    // The set should not contain 0, as that would mean that two points have the same coordinates
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    return !set.contains(0) && set.size() == 2;
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  }
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  // This method calculates the distance between two points and returns its square
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  private int distanceSquare(int[] a, int[] b) {
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    // We use the Pythagorean theorem to calculate the distance between the points
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    return (a[0] - b[0]) * (a[0] - b[0]) + (a[1] - b[1]) * (a[1] - b[1]);
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  }
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}