推 ikari512:現在的問題是如果九億個都被用光是否會override的問題^^" 07/24 01:22
→ ikari512:不是hash的問題喔.. 07/24 01:23
推 cpcmce:你的第一行沒辦法推到第二行的結論吧 07/24 04:19
推 proLIONS:The same string of course will output the same hash 07/24 07:11
→ proLIONS:value. The problem is will two different string map 07/24 07:12
→ proLIONS:to ONE hash value, and it's so called hash collision. 07/24 07:13
我想請教一下
如果說今天是參照別的資訊(例如DB中最久沒用縮址的日期)
而造成的Hash collision還算是Hash collision嗎？
wikipedia的定義是：
In computer science, a hash collision is a situation that occurs when
two distinct inputs into a hash function produce identical outputs.
就是說 明明output不同 但是為了別的理由把他map到之前用過的output
不知道這樣算不算？
抱歉....借用google版討論一下 ><
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推 xanthous2:既然討論hash collision 先搞清楚"hash function"是啥 07/24 11:44
→ xanthous2:如果額外的mapping是對hash output做的 那不是hash問題 07/24 11:49
推 proLIONS:Your thinking is quiet interesting. This extra 07/25 02:12
→ proLIONS:processing may somehow relieve the hash collision 07/25 02:13
→ proLIONS:problem. However, just as what 1st floor says, 07/25 02:13
→ proLIONS:it beyonds the operation of a basic hash function. 07/25 02:13
→ proLIONS:and may take extra computational cost due to 07/25 02:14
→ proLIONS:breaking the regularity of hash functions. 07/25 02:15
→ ikari512:感謝 所以說對hash collision做處理不屬於hash function? 07/25 17:41