hackerrank-frequency-queries.py

from collections import Counter
def freqQuery(queries):
    items = Counter()
    checks = Counter()
    res = []
    for couple in queries:
        query, item = couple
        if query == 1:
            checks[items[item]] -= 1
            items[item] += 1
            checks[items[item]] += 1
        elif query == 2:
            if checks[item] > 0:
                checks[items[item]] -= 1
                items[item] -= 1
                checks[items[item]] += 1
        else:
            if checks[item] > 0:
                res.append(1)
            else:
                res.append(0)
    return res