Secret Santa Assigner

Randomsingle-cycleSecretSantaassignmentnoselfgifts,not uniformoverall derangementsor exclusionrule CSP. Boundedoffline arithmetic/sampling only;not gambling advice,fair physical randomness,secure randomness or predictive certainty.

Description

A single-cycle Secret Santa draw gives every participant one recipient and avoids self-gifts.

A single-cycle Secret Santa draw gives every participant one recipient and avoids self-gifts.^[1]

Its distribution is limited to cycle assignments, so it does not sample every possible derangement.

When to use Secret Santa Assigner

Use this tool to apply the stated secret santa assigner operation with an explicit input and unit basis.

How to use Secret Santa Assigner and how it works

Establish the text or game convention described above.
Enter seed, actualParticipants and run the tool.
Read result.givers, result.receivers using the output meanings below.
If input is rejected, correct the stated type, range, ordering or alignment issue and rerun; review successful results under the declared convention.

Input field	Meaning	Value type	Requirement
seed	Nonblank reproducibility string, at most 256 characters; required even with a supplied random source.	string	required; further conditions in the algorithm
actualParticipants	Participants, on the basis specified in the algorithm.	array of string	required; dense; align related rows as specified; at most 128 strings; 128 UTF-16 units each; further conditions in the algorithm

Require at least two distinct participants. Shuffle them, use that order as givers, and rotate it left by one as receivers. A nonblank seed of at most 256 characters selects the existing seeded generator unless execution context supplies random. One source advances through the request; supplied samples must be finite in [0,1). These draws are not cryptographically secure.

The default source hashes the seed’s UTF-16 units into an integer state and advances a deterministic arithmetic generator for each sample. A supplied execution-context random source takes precedence; it must return finite values in [0,1). The required seed still must be nonblank and at most 256 characters. These draws are reproducible entertainment or sampling, without cryptographic unpredictability.^[2]

receiverᵢ = shuffled participants[(i+1) mod n]

Apply the declared units, ordering and branch conditions.

Output field	Meaning	Value type
result	Object containing the declared output fields.	object
result.givers	Shuffled participants defining giver order.	array
result.receivers	Same participants rotated one place, aligned with givers.	array

json

{
  "input": {
    "seed": "batch51",
    "actualParticipants": [
      "A",
      "B",
      "C"
    ]
  },
  "output": {
    "result": {
      "givers": [
        "C",
        "A",
        "B"
      ],
      "receivers": [
        "A",
        "B",
        "C"
      ]
    }
  }
}

Limitations and assumptions

The output applies the declared operation to the values you supply. Establish the measurement basis, units, coefficients and any caller-selected rules before interpreting it. The tool does not independently collect or verify observations or decide whether a model or reference applies.

Supply explicit required fields with the documented types and dense aligned arrays. Unknown fields, wrong types and nonfinite numbers are rejected. Branch-specific constraints are explained above. A successful false boolean, negative signed difference, empty slice or unresolved tie is distinct from an input error. Very large inputs or outputs may be rejected by shared resource limits.

Alternative or Complementary methods

For a related operation, use White Elephant Order Shuffler. A white-elephant gift exchange needs a turn order before its house rules are applied.

For a related operation, use Werewolf Role Dealer. Werewolf roles are dealt from a role inventory whose balance has already been chosen.

References

Secret Santa Assigner — tool.io
Existing seeded random generator — tool.io

Similar or alternative tools

White Elephant Order Shuffler
A white-elephant gift exchange needs a turn order before its house rules are applied.
Werewolf Role Dealer
Werewolf roles are dealt from a role inventory whose balance has already been chosen.