Astemir Eleev eleev
glukianets
/ 8Queens.swift
Created
August 15, 2024 15:38
Naive 8Queens puzzle solution with bitmasks
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| func queen(atFile file: Int, rank: Int) -> UInt64 { | |
| 0b00000001_00000001_00000001_00000001_00000001_00000001_00000001_00000001 << (file) | | |
| 0b00000000_00000000_00000000_00000000_00000000_00000000_00000000_11111111 << (rank * 8) | | |
| 0b10000000_01000000_00100000_00010000_00001000_00000100_00000010_00000001 >> ((file - rank) * 8) | | |
| 0b00000001_00000010_00000100_00001000_00010000_00100000_01000000_10000000 >> ((7 - file - rank) * 8) | |
| } | |
| func occupiedIndices(in board: UInt64) -> some Sequence<(file: Int, rank: Int)> { | |
| sequence(state: (board, 0)) { state in | |
| let offset = state.0.trailingZeroBitCount |
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