<h2 id="heading-definition">Definition</h2>
<p>one of the hash function's problems.</p>
<p>If the input value is different, the output value should be different.
But, the output is same.</p>
<ul>
<li>Less hash crush is better</li>
<li>No hash crush is almost impossible. We calls that "perfect hash function"</li>
<li>If you limited insert value a lot, you may create the perfect hash function</li>
</ul>
<h2 id="heading-example-of-hash-crash">Example of Hash Crash</h2>
<p>insert "A" --Hash Function--&gt; return "3"</p>
<p>insert "B" --Hash Function--&gt; return "1"</p>
<p>insert "C" --Hash Function--&gt; return "3"</p>
<p>inserted values are different, but the returned values are same</p>


## Definition

one of the hash function's problems.

If the input value is different, the output value should be different.
But, the output is same.

- Less hash crush is better
- No hash crush is almost impossible. We calls that "perfect hash function"
- If you limited insert value a lot, you may create the perfect hash function

## Example of Hash Crash
insert "A" --Hash Function--> return "3"

insert "B" --Hash Function--> return "1"

insert "C" --Hash Function--> return "3"

inserted values are different, but the returned values are same



Hash Crash or Hash Collision

Definition

Example of Hash Crash