Encoding

The original data will be encoded with this code table as follows:

   Symbol   Frequency   Code Word
       a      5          0
       b      2          10
       r      2          111
       c      1          1101
       d      1          1100

   a b  r   a c    a d    a b  r   a
   0 10 111 0 1101 0 1100 0 10 111 0

   encoded data:  23 Bit
   original data: 33 Bit

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