RosettaCodeData/Task/Caesar-cipher/V-(Vlang)/caesar-cipher.v

import rand

const lo_abc = 'abcdefghijklmnopqrstuvwxyz'
const up_abc = 'ABCDEFGHIJKLMNIPQRSTUVWXYZ'

fn main() {
   key := rand.int_in_range(2, 25) or {13}
   encrypted := caesar_encrypt('The five boxing wizards jump quickly', key)
   println(encrypted)
   println(caesar_decrypt(encrypted, key))
}

fn caesar_encrypt(str string, key int) string {
   offset := key % 26
   if offset == 0 {return str}
   mut nchr := u8(0)
   mut chr_arr := []u8{}
   for chr in str {
      if chr.ascii_str() in up_abc.split('') {
         nchr = chr + u8(offset)
         if nchr > u8(90) {nchr -= 26}
      }
      else if chr.ascii_str() in lo_abc.split('') {
         nchr = chr + u8(offset)
         if nchr > u8(122) {nchr -= 26}
      }
      else {nchr = chr}
      chr_arr << nchr
   }
   return chr_arr.bytestr()
}

fn caesar_decrypt(str string, key int) string {
   return caesar_encrypt(str, 26 - key)
}