Hamming (7,4) Syndrome

Problem

Compute the integer syndrome of a received 7-bit word for the systematic Hamming(7,4) code. Evaluate s1 = c1^c3^c5^c7, s2 = c2^c3^c6^c7 and s4 = c4^c5^c6^c7, then return s1 + 2 * s2 + 4 * s4. The result is 0 for a valid codeword and gives the 1-indexed error position otherwise.

Hint

The syndrome bits are read as a little-endian binary position number.

Test cases

case 1

in: [[0,0,0,0,0,0,0]]

expected: 0

case 2

in: [[1,1,1,0,0,0,0]]

expected: 0

case 3

in: [[0,1,1,0,0,0,0]]

expected: 1

case 4

in: [[0,0,0,0,1,0,0]]

expected: 5

Starter codePython

def hamming74_syndrome(received):
    # Your code here
    pass

4 test cases · run your code against them in the editor