         }
         return result;
     }
-    //MARK - 322. Coin Change
+    //MARK: - 322. Coin Change
     func coinChange(_ coins: [Int], _ amount: Int) -> Int {
         if amount == 0 {
             return 0
         }
         let len = coins.count
-        var nums:[Int] = Array.init(repeating: 0, count: amount + 1)
-        nums[0] = 0
-        for i in 0 ... amount {
-            nums[i] = Int.max - 1
-        }
+        var nums:[Int] = Array.init(repeating: Int.max - 1, count: amount + 1)
         for i in 0 ..< len {
             if coins[i] <= amount {
                 nums[coins[i]] = 1

        head.next = l1 != nil ? l1 : l2
        return result.next
    }
    //MARK - 231. Power of Two
    func isPowerOfTwo(_ n: Int) -> Bool {
        return n > 0 && (n & (n - 1) == 0)
    }

        } while num >= 1
        return result
    }
    //MARK: - 148. Sort List
    func sortList(_ head: ListNode?) -> ListNode? {
        if head == nil {
            return nil
