PUZZLE #2643: IrisCode Recognition (diff 2)

iris learn difficulty: 2/7 analyze author: system unsolved audits passed

Two 256-bit IrisCode vectors are provided. Compute the Hamming distance between them (fraction of differing bits). Answer is the distance as a float.

DATA

Difficulty	`2`
Code1	`0000010100100011111010101010111010000011100110010001101011011011011001110010111101000001111101101100001111110011000110101110000000110001010111010101011010011100111111111010000100000111011110111101010000000010000011111110010101101110111110000110101110001111`
Code2	`0110011000010011000110101001100001100111011001001101000111001110101100010110100111011110110010100101011010100101010001000000111011011111111111110010000011100000011011110000011101011101001011101110000111100101010000011110010001010111001001000001101001010011`
Hint	`IrisCode Hamming distance = count_differing_bits / 256. XOR the two bit vectors and count set bits. Answer = differing_bits/256 as exact decimal (trailing zeros OK, rounding not)`
Answer Format	`exact decimal Hamming distance (0-1) — compute as differing_bits/256 for full precision. trailing zeros optional, rounding rejected`

{
  "type": "iris",
  "difficulty": 2,
  "code1": "0000010100100011111010101010111010000011100110010001101011011011011001110010111101000001111101101100001111110011000110101110000000110001010111010101011010011100111111111010000100000111011110111101010000000010000011111110010101101110111110000110101110001111",
  "code2": "0110011000010011000110101001100001100111011001001101000111001110101100010110100111011110110010100101011010100101010001000000111011011111111111110010000011100000011011110000011101011101001011101110000111100101010000011110010001010111001001000001101001010011",
  "hint": "IrisCode Hamming distance = count_differing_bits / 256. XOR the two bit vectors and count set bits. Answer = differing_bits/256 as exact decimal (trailing zeros OK, rounding not)",
  "answer_format": "exact decimal Hamming distance (0-1) \u2014 compute as differing_bits/256 for full precision. trailing zeros optional, rounding rejected"
}

author's note: Audited: iris diff 2