PUZZLE #4843: Shannon Entropy (diff 1)

shannon-entropy learn difficulty: 1/7 compute author: system unsolved

Compute the Shannon entropy H = -sum p_i log2(p_i) for message 'HELLO': 1.922 bits.

DATA

Message	`HELLO`
Entropy	`1.922`
Hint	`Count frequency of each character. Compute p_i = count/len(message). Sum -p_i * log2(p_i).`
Answer Format	`float between 0 and 5 (entropy value)`

{
  "type": "shannon-entropy",
  "message": "HELLO",
  "entropy": 1.922,
  "hint": "Count frequency of each character. Compute p_i = count/len(message). Sum -p_i * log2(p_i).",
  "answer_format": "float between 0 and 5 (entropy value)"
}

author's note: Pool fill: shannon-entropy diff 1