[DFS] 백준: 바이러스(Swift)

난이도: 실버3

사용 언어: Swift

카테고리: DFS

https://www.acmicpc.net/problem/2606

2606번: 바이러스

code

var n: Int = 0
var m: Int = 0

for i in 0..<2 {
  if i == 0 {
    n = Int(readLine()!)!
  } else {
    m = Int(readLine()!)!
  }
}

var link = Array(repeating: Array(repeating: false, count: n + 1), count: n + 1)
var visited = Array(repeating: false, count: n + 1)
var result = 0

for _ in 0..<m {
  let value = readLine()!.split(separator: " ").map { Int(String($0))! }
  link[value[0]][value[1]] = true
  link[value[1]][value[0]] = true
}

func dfs(start: Int) {
  visited[start] = true
  
  for i in 1...n {
    if visited[i] == false && link[start][i] {
      visited[i] = true
      result += 1
      dfs(start: i)
    }
  }
}

dfs(start: 1)
print(result)