FastPrep
Problem · Array

Fixed-Range Frequency Count

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Problem statement

Given an array of integers, count how many times each value appears. Every value is in the fixed domain from 0 through 65535, inclusive.

Use a direct frequency array indexed by the input value. Return only values with positive frequency as strings value|count, ordered by numeric value in ascending order.

Function

countFixedRangeFrequencies(values: int[]) → String[]

Examples

Example 1

values = [2,65535,2,0,65535,2]return = ["0|1","2|3","65535|2"]

The value 0 appears once, 2 appears three times, and the largest domain value appears twice.

Example 2

values = [5,4,5,4,3]return = ["3|1","4|2","5|2"]

Results are emitted in numeric value order regardless of the first occurrence order.

Constraints

  • 0 <= values.length <= 200000.
  • 0 <= values[i] < 65536.
  • Every frequency fits in a signed 32-bit integer.

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public String[] countFixedRangeFrequencies(int[] values) {
    // write your code here
}
values[2,65535,2,0,65535,2]
expected["0|1", "2|3", "65535|2"]
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