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# 2080. Range Frequency Queries
from collections import defaultdict
from bisect import bisect
"""
design a data structure to find the frequency of a given value in a given
subarray. the frequency of a value in a subarray is the number of occurences
of that value in the subarray. implement the 'RangeFreqQuery' class:
'rangeFreqQueryCreate(int[] arr)' constructs an instance of the class with
the given 0-indexed integer array 'arr'. 'int RangeFreqQuery(int left, int
right, int val)' returns the frequency of 'val' in the subarray 'arr[left ...
right]'. a subarray is contiguous sequence of elements within an array.
'arr[left ... right]' denotes the subarray that contains the elements of
'nums' between indices 'left' and 'right' inclusively
"""
class RangeFreqQuery(object):
def __init__(self, arr):
"""
:type arr: List[int]
"""
self.cnt = defaultdict(list)
for i, j in enumerate(arr):
self.cnt[j].append(i)
def query(self, left, right, value):
"""
:type left: int
:type right: int
:type value: int
:rtype: int
"""
i = bisect(self.cnt[value], left - 1)
j = bisect(self.cnt[value], right)
return j - i
if __name__ == "__main__":
obj = RangeFreqQuery([12, 33, 4, 56, 22, 2, 34, 33, 22, 12, 34, 56])
print(obj.query(1, 2, 4))
print(obj.query(0, 11, 33))
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