7544 - Construct Tuple

[teamchong]

type ConstructTuple<L extends number, Output extends string = `${L}`> =
  Output extends `${infer Prefix extends string}${keyof N}`
    ? N<ConstructTuple<L, Prefix>>[Output extends `${Prefix}${infer D extends keyof N}` ? D : never]
  : []

type N<T extends unknown[] = []> = {
  '0': [...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T],
  '1': [...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, unknown],
  '2': [...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, unknown, unknown],
  '3': [...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, unknown, unknown, unknown],
  '4': [...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, unknown, unknown, unknown, unknown],
  '5': [...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, unknown, unknown, unknown, unknown, unknown],
  '6': [...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, unknown, unknown, unknown, unknown, unknown, unknown],
  '7': [...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, unknown, unknown, unknown, unknown, unknown, unknown, unknown],
  '8': [...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, unknown, unknown, unknown, unknown, unknown, unknown, unknown, unknown],
  '9': [...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, ...T, unknown, unknown, unknown, unknown, unknown, unknown, unknown, unknown, unknown],
}

Playground

[flyFatSeal]

perfect answer