Subset Complement Indexes

Complement a unique explicit index subset against a bounded 0..size-1 universe, returning ascending omitted indexes.

Description

Complement a unique explicit index subset against a bounded 0..size-1 universe, returning ascending omitted indexes.

A subset complement contains precisely the universe indexes not supplied. The universe here is the integer range starting at zero.

When to use this tool

Complement a unique explicit index subset against a bounded 0..size-1 universe, returning ascending omitted indexes.

  • Prepare the supplied indexes, size fields for this operation.
  • Compare the complete example with the representation used by your own input before carrying the result into another step.

How to use the tool and how it works

  1. Enter indexes, size. Use the exact text syntax, units and index conventions explained below.
  2. Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
  3. Read result.indexes. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.

Sort a copy to validate unique integer indexes inside size, then return missing indexes in ascending order.1

Input fieldMeaning and representationAccepted input
indexesindexes.List of finite numbers; at most 128 entries
sizesize.Safe integer
Output fieldInterpretation
resultObject containing the named outputs below.
result.indexesThe indexes list in the ordering and representation described above.
json
{
  "input": {
    "indexes": [
      0,
      3
    ],
    "size": 4
  },
  "output": {
    "result": {
      "indexes": [
        1,
        2
      ]
    }
  }
}

Limitations and assumptions

  • size is at most 128. Duplicate indexes are errors, and the original input need not already be sorted.
  • All declared input fields are required and unexpected top-level fields are rejected. Numbers must be finite; lists are limited to 128 entries and ordinary text fields to 8,192 UTF-16 code units, with tighter limits where stated.
  • JSON text inputs must parse within bounded nesting and size limits. Numeric outputs outside the safe finite range are rejected; large exact integer results use decimal strings. Indexes and half-open spans are zero-based unless a rank is explicitly described as one-based.

Alternative or Complementary methods

Retain the universe size, subset size and ordering convention with a rank. Use rank/unrank pairs from the same convention and distinguish subset masks from lexicographic indexes.

References

  1. Tool behavior and example: Subset Complement Indexes — tool.io

Similar or alternative tools

  • Next Combination Indexes

    Return the next lexicographic fixed-size index combination without wrapping; null marks the order boundary.

  • Previous Combination Indexes

    Return the previous lexicographic fixed-size index combination without wrapping; null marks the order boundary.

Don't forget to set a bookmark for tool.io!
Privacy | Imprint | Cookies