Instance Methodswift-algorithms 1.2.1Algorithms->Swift

    permutations(ofCount:)

    Returns a collection of the permutations of this collection with lengths in the specified range.

    Permutations.swift:331
    func permutations<R>(ofCount kRange: R) -> PermutationsSequence<Self> where R : RangeExpression, R.Bound == Int
    Mangled symbol
    sSl10AlgorithmsE12permutations7ofCountAA20PermutationsSequenceVyxGqd___tSXRd__Si5BoundRtd__lF What are these?
    FNV24 hash
    5ZVHN

    Parameters

    kRange

    A range of the number of elements to include in each permutation. kRange can be any integer range expression, and is clamped to the number of elements in this collection. Passing a range covering sizes greater than the number of elements in this collection results in an empty sequence.

    This example prints the different permutations of one to two elements from an array of three names:

    let names = ["Alex", "Celeste", "Davide"]
for perm in names.permutations(ofCount: 1...2) {
    print(perm.joined(separator: ", "))
}
// Alex
// Celeste
// Davide
// Alex, Celeste
// Alex, Davide
// Celeste, Alex
// Celeste, Davide
// Davide, Alex
// Davide, Celeste

    This example prints all the permutations (including an empty array) from an array of numbers:

    let numbers = [10, 20, 30]
for perm in numbers.permutations(ofCount: 0...) {
    print(perm)
}
// []
// [10]
// [20]
// [30]
// [10, 20]
// [10, 30]
// [20, 10]
// [20, 30]
// [30, 10]
// [30, 20]
// [10, 20, 30]
// [10, 30, 20]
// [20, 10, 30]
// [20, 30, 10]
// [30, 10, 20]
// [30, 20, 10]

    The returned permutations are in ascending order by length, and then lexicographically within each group of the same length.