EasyNLPnlp-018

Hapax Count

Problem

Return the number of distinct tokens that occur exactly once in the token list.

Count types, not occurrences, so a token repeated twice contributes nothing.

Hint

Build a frequency table, then count entries equal to 1.

case 1

in: [["a","b","c","a"]]

expected: 2

case 2

in: [["a","a","a"]]

expected: 0

case 3

in: [[]]

expected: 0

case 4

in: [["x","y","z"]]

expected: 3

Starter codePython

def hapax_count(tokens):
    # Your code here
    pass

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