Files
aoc24/day04/d04p2.swift
2024-12-12 18:16:45 -08:00

22 lines
793 B
Swift

import Foundation
func readInput(_ filePath: String) throws -> [[Character]] {
let content = try String(contentsOfFile: filePath, encoding: .ascii)
return content.split(separator: "\n").map(Array.init)
}
let MAS: (Character, Character, Character) = ("M", "A", "S")
func dX(_ map: [[Character]], _ i: Int, _ j: Int) -> Bool {
return ((map[i-1][j-1], map[i][j], map[i+1][j+1]) == MAS
|| (map[i+1][j+1], map[i][j], map[i-1][j-1]) == MAS)
&& ((map[i-1][j+1], map[i][j], map[i+1][j-1]) == MAS
|| (map[i+1][j-1], map[i][j], map[i-1][j+1]) == MAS)
}
let input = try readInput(CommandLine.arguments[1])
let answer = (1..<input.count-1).reduce(0, { n, i in
n + (1..<input[i].count-1).reduce(0, { n, j in dX(input, i, j) ? n+1 : n })
})
print(answer)