ExchangeLuckyDraw
A lucky draw program for Luobotou IT Forum.
This program uses currency exchange rate as random source.
How it is working
https://www.safe.gov.cn/AppStructured/hlw/RMBQuery.do The RMB central parity(RATE) is updated on 9:15 am every workday.
For example, the maximum floor of the thread is 30#, there are 29 valid replies excludes the post owner. If we draw 5 people from 29 replies,
On 2023-02-20,there are 24 RATEs on the webside, which are:
686.43 733.3 5.1102 87.535 825.69 64.499 1075.97 471.47 509.05 427.94 513.49 742.28 263.02 18903.0 53.51 54.636 5236.17 64.93 101.55 152.38 150.03 274.525 267.64 501.91
Take the first number as example:
- remove the dot point, got 68643
- divide by floor number - 1 (29), mod, got 0, then 0+2 = 2#, the 2# floor is the lucky floor (floor number starts from 1#).
And so on, if the number is replicated, take the next one.
Advantage:
- Everyone can calculate the lucky floor after the RATE released, and it is impossible for 'covert operation' .