2021_CodeJam_ReversortEngineering.swift

//: [Previous](@previous)

import Foundation

let input = """
7
4 6
2 1
7 12
7 2
2 1000
77 298
100 500
"""
var lines = input.components(separatedBy: "\n")
func readLine() -> String? {
    let firstStr = lines.first
    lines.remove(at: 0)
    return firstStr!
}
func getIntegersOf(line: String, separatedBy separator: String) -> [Int] {
    let stringArray = line.components(separatedBy: separator)
    return stringArray.map { Int($0)! }
}

// Reversort
func checkSort(arr: [Int], count: Int)-> Bool {
    let result = doSomething(arr)
    return count == result
}


func doSomething(_ input: [Int])-> Int {
    var result: Int = 0
    var input = input
    // (i, exchange)
    for i in 0..<input.count - 1 {
        var exchange = i
        var min: Int = input[i]
        for j in i + 1..<input.count {
            if min > input[j] {
                min = input[j]
                exchange = j
            }
        }
        let reversed = Array(input[i...exchange].reversed())
        for k in i...exchange {
            input[k] = reversed[k - i]
        }
        result += ( exchange - i + 1)
    }
    return result
}

func createArray(range: Int)-> [Int] {
    var result: [Int] = []
    for i in 1...range {
        result.append(i)
    }
    return result
}


func checkList(arr: [Int], cas: Int, count: Int)-> String {
    var arr = arr
    if checkSort(arr: arr, count: count) {
        let string = arr.map{ String($0)}.joined(separator: " ")
        let result = "Case #\(cas): \(string)"
        return result
    }
    for i in arr.indices {
        for j in i + 1..<arr.count {
            let num = arr[i]
            arr[i] = arr[j]
            arr[j] = num
            if checkSort(arr: arr, count: count) {
                let string = arr.map{ String($0)}.joined(separator: " ")
                let result = "Case #\(cas): \(string)"
                return result
            }
        }
    }
    return "Case #\(cas): IMPOSSIBLE"
}

func check(line: String, cas: Int)-> String {
    let lineArr = getIntegersOf(line: line, separatedBy: " ")
    let n = lineArr[0]
    let c = lineArr[1]
    let arr = createArray(range: n)
    return checkList(arr: arr, cas: cas, count: c)
}

let t: Int = Int(readLine()!)!
var cas: Int = 0

while cas < t {
    cas += 1
   print(check(line: readLine()!, cas: cas))

}