[HashCollision][哈希冲突][HashValue]:最佳哈希质数

小灰灰 2022-10-15 00:38 205阅读 0赞

**个人使用:**  
**解决哈希冲突的方法有很多,所以,希望大家可以根据自己心中所想来解决,此方法非唯一标准**.

规则:

> 1.  列表中的每个数字都是质数
> 2.  每个数字都略小于前一个数字的两倍
> 3.  每个数字都尽可能远离最接近的2的2次方

所有符合上面三个标准的数字,都可以在各自的区间极少的减轻哈希冲突.  
可以按照这个标准,来通过电脑计算得出.  
用以下列表给出的质数,可以让你的哈希函数计算得出的哈希值,在下列区间内,最优的解决哈希冲突(HashCollision)

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<table> 
 <thead> 
  <tr> 
   <th>下限(DEC)</th> 
   <th>上限(DEC)</th> 
   <th>区间相对偏差(%)</th> 
   <th>质数(DEC)</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>32 (2^5)</td> 
   <td>64 (2^6)</td> 
   <td>10</td> 
   <td>53</td> 
  </tr> 
  <tr> 
   <td>64 (2^6)</td> 
   <td>128 (2^7)</td> 
   <td>1</td> 
   <td>97</td> 
  </tr> 
  <tr> 
   <td>128 (2^7)</td> 
   <td>256 (2^8)</td> 
   <td>0</td> 
   <td>193</td> 
  </tr> 
  <tr> 
   <td>256 (2^8)</td> 
   <td>512 (2^9)</td> 
   <td>1</td> 
   <td>389</td> 
  </tr> 
  <tr> 
   <td>512 (2^9)</td> 
   <td>1,024 (2^10)</td> 
   <td>0</td> 
   <td>769</td> 
  </tr> 
  <tr> 
   <td>1,024 (2^10)</td> 
   <td>2,048 (2^11)</td> 
   <td>0</td> 
   <td>1,543</td> 
  </tr> 
  <tr> 
   <td>2,048 (2^11)</td> 
   <td>4,096 (2^12)</td> 
   <td>0</td> 
   <td>3,079</td> 
  </tr> 
  <tr> 
   <td>4,096 (2^12)</td> 
   <td>8,192 (2^13)</td> 
   <td>0</td> 
   <td>6,151</td> 
  </tr> 
  <tr> 
   <td>8,192 (2^13)</td> 
   <td>16,384 (2^14)</td> 
   <td>0</td> 
   <td>12,289</td> 
  </tr> 
  <tr> 
   <td>16,384 (2^14)</td> 
   <td>32,768 (2^15)</td> 
   <td>0</td> 
   <td>24,593</td> 
  </tr> 
  <tr> 
   <td>32,768 (2^15)</td> 
   <td>65,536 (2^16)</td> 
   <td>0</td> 
   <td>49,157</td> 
  </tr> 
  <tr> 
   <td>65,536 (2^16)</td> 
   <td>131,072 (2^17)</td> 
   <td>0</td> 
   <td>98,317</td> 
  </tr> 
  <tr> 
   <td>131,072 (2^17)</td> 
   <td>262,144 (2^18)</td> 
   <td>0</td> 
   <td>196,613</td> 
  </tr> 
  <tr> 
   <td>262,144 (2^18)</td> 
   <td>524,288 (2^19)</td> 
   <td>0</td> 
   <td>393,241</td> 
  </tr> 
  <tr> 
   <td>524,288 (2^19)</td> 
   <td>1,0485,76 (2^20)</td> 
   <td>0</td> 
   <td>786,433</td> 
  </tr> 
  <tr> 
   <td>1,048,576 (2^20)</td> 
   <td>2,097,152 (2^21)</td> 
   <td>0</td> 
   <td>1,572,869</td> 
  </tr> 
  <tr> 
   <td>2,097,152 (2^21)</td> 
   <td>4,194,304 (2^22)</td> 
   <td>0</td> 
   <td>3,145,739</td> 
  </tr> 
  <tr> 
   <td>4,194,304 (2^22)</td> 
   <td>8,388,608 (2^23)</td> 
   <td>0</td> 
   <td>6,291,469</td> 
  </tr> 
  <tr> 
   <td>8,388,608 (2^23)</td> 
   <td>16,777,216 (2^24)</td> 
   <td>0</td> 
   <td>12,582,917</td> 
  </tr> 
  <tr> 
   <td>16,777,216 (2^24)</td> 
   <td>33,554,432 (2^25)</td> 
   <td>0</td> 
   <td>25,165,843</td> 
  </tr> 
  <tr> 
   <td>33,554,432 (2^25)</td> 
   <td>67,108,864 (2^26)</td> 
   <td>0</td> 
   <td>50,331,653</td> 
  </tr> 
  <tr> 
   <td>67,108,864 (2^26)</td> 
   <td>134,217,728 (2^27)</td> 
   <td>0</td> 
   <td>100,663,319</td> 
  </tr> 
  <tr> 
   <td>134,217,728 (2^27)</td> 
   <td>268,435,456 (2^28)</td> 
   <td>0</td> 
   <td>201,326,611</td> 
  </tr> 
  <tr> 
   <td>268,435,456 (2^28)</td> 
   <td>536,870,912 (2^29)</td> 
   <td>0</td> 
   <td>402,653,189</td> 
  </tr> 
  <tr> 
   <td>536,870,912 (2^29)</td> 
   <td>1,073,741,824 (2^30)</td> 
   <td>0</td> 
   <td>805,306,457</td> 
  </tr> 
  <tr> 
   <td>1,073,741,824 (2^30)</td> 
   <td>2,147,483,648 (2^31)</td> 
   <td>0</td> 
   <td>1,610,612,741</td> 
  </tr> 
 </tbody> 
</table>

**区间相对偏差是约百分比,不是绝对百分比**  
**不保证数值最优**

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