Submission #41809469

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Source Code Expand

import Foundation

struct Edge: Hashable {
  let u: Int
  let v: Int
  
  init(_ u: Int, _ v: Int) {
    self.u = min(u, v)
    self.v = max(u, v)
  }
}

func main() {
  var scanner = Scanner()
  let N = scanner.read(Int.self)
  let D = scanner.read(Int.self)
  var G = Set<Edge>()
  for i in 0 ..< N {
    for d in -D ... D {
      var j = (i + d) % N
      if j < 0 {
        j += N
      }
      if i != j {
        G.insert(Edge(i, j))
      }
    }
  }
  if G.count < N * D {
    print("No")
  } else {
    print("Yes")
    for e in G {
      print(e.u + 1, e.v + 1)
    }
  }
}

main()

struct Scanner {
  private var tokens = [String]()
  private var index = 0
  
  mutating func read<T>(_ type: T.Type) -> T where T: LosslessStringConvertible {
    T(read())!
  }
  
  mutating func read<T>(_ type: T.Type, count n: Int) -> [T] where T: LosslessStringConvertible {
    (0 ..< n).map { _ in read(type) }
  }
  
  private mutating func read() -> String {
    while tokens.count == index {
      tokens = readLine()!.split(separator: " ").map(\.description)
      index = 0
    }
    defer {
      index += 1
    }
    return tokens[index]
  }
}

Submission Info

Judge Result