#can a hashset have empty buckets?

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slow spoke
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same

lusty scaffoldBOT
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<@&987246399047479336> please have a look, thanks.

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No, a HashSet in Java does not have empty buckets. The internal implementation of a HashSet uses a hash table, where each bucket contains a linked list of elements with the same hash code. If there are no elements with the same hash code, the bucket will be empty (i.e., it will not contain any elements). However, the bucket itself still exists in memory as part of the hash table structure.

slow spoke
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okay

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so what if i want the hash code to be the value of the integer itself but the size of the hash set is only 10

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how would i do that

lusty scaffoldBOT
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If you want the hash code to be the value of the integer itself, but limit the size of the hash set to 10, you can use a technique called modulo hashing.

In modulo hashing, you calculate the hash code by taking the remainder of dividing the integer value by the size of the hash set. In your case, since the size is 10, you would calculate hashcode = value % 10.

Here's an example implementation in Java:

int value = 42; // The integer value
int setSize = 10; // Size of the hash set

int hashCode = value % setSize; // Calculate the hash code

System.out.println(hashCode); // Output: 2

In this example, if value is 42 and setSize is 10, then hashCode will be calculated as 42 % 10, which equals 2.

By using modulo hashing, you can ensure that your hash code will always be within the range of your desired size (in this case, between 0 and 9).

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If you want the hash code to be the value of the integer itself, but the size of the hash set is only 16, you can use a simple hashing function to map the value to a valid index within the range of 0-15.

To add the value 99 to the hash set, you would follow these steps:

  1. Calculate the hash code for the value 99. Since you want the hash code to be equal to the value itself, in this case, it would be 99.

  2. To map this hash code to a valid index within the range of 0-15, you can use modulo division by 16. So, calculate 99 % 16, which equals 3.

  3. Check if there is already an element at index 3 in your hash set. If there is no element present at that index, add 99 at that position.

If there is already an element present at index 3 (collision), you would need to handle it according to your desired collision resolution strategy (e.g., chaining or linear probing).

winged mantle
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your hashCode gets mapped to the index using modulo of the size, and if two end up at the same index they get put together in a bucket (linked list)

pure panther
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But why do you want to do that?