Count how many integers in a given range are not special, where special numbers are defined by a problem-specific numeric rule.
Count the number of non-special integers in a range
gfgProblem
You are given a range of integers and a rule that marks some numbers in that range as special. Your task is to count how many numbers in the range are not special.
In the most common formulation of this problem, a number is special if it satisfies a certain divisor-based condition, and you must return the number of integers in the inclusive range that do not satisfy it.
Goal
Compute the count of non-special numbers efficiently for the provided range.
Notes
- The range is inclusive.
- A number may be special due to a property derived from its factors/divisors.
- A direct check of every possible value can be too slow for large bounds, so an efficient counting approach is expected.
Input Format
- A range described by two integers, typically
landr, withl <= r. - The exact special-number rule is part of the problem definition.
Input
clike
l rOutput Format
- Return a single integer: the number of integers in the inclusive range
[l, r]that are not special.
Output
clike
countConstraints
1 <= l <= r- Bounds are intended to be large enough that naive enumeration may be inefficient.
- Use 64-bit arithmetic where needed.
Example 1
Input
l = 1, r = 10
Output
8
Explanation
If 2 numbers in the range are special, then the remaining 8 are not special. This example illustrates the counting objective.
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