Swift 算法优化：翻转游戏

class Solution {\n func flipgame(_ fronts: [Int], _ backs: [Int]) -> Int {\n var minNum = Int.max\n let n = fronts.count\n var numSet = Set()\n \n for i in 0..<n {\n if fronts[i] == backs[i] {\n numSet.insert(fronts[i])\n }\n }\n \n for num in fronts + backs {\n if !numSet.contains(num) {\n minNum = min(minNum, num)\n }\n }\n \n return minNum == Int.max ? 0 : minNum\n }\n}