30575 - BitwiseXOR

[lvjiaxuan]

type Reverse<S extends string> = S extends `${infer First}${infer Rest}` ? `${Reverse<Rest>}${First}` : ''

type GetLastAndRest<S extends string, _S extends string = Reverse<S>>
  = _S extends `${infer Last extends string}${infer Rest extends string}`
    ? { Last: Last, Rest: Reverse<Rest> }
    : { Last: '', Rest: '' }

type XOR<S1 extends string, S2 extends string> = S1 extends S2 ? '0' : '1'

type BitwiseXOR<
  S1 extends string,
  S2 extends string,
  _S1 extends { Last: string, Rest: string } = GetLastAndRest<S1>,
  _S2 extends { Last: string, Rest: string } = GetLastAndRest<S2>
> = `${ _S1['Rest'] }${ _S2['Rest'] }` extends ''
    ? `${XOR<_S1['Last'], _S2['Last']>}`
    : `${BitwiseXOR<_S1['Rest'], _S2['Rest']>}${XOR<_S1['Last'], _S2['Last']>}`