[Swift]LeetCode926. 将字符串翻转到单调递增 | Flip String to

 1 class Solution {
 2     func minFlipsMonoIncr(_ S: String) -> Int {
 3         var arr:[Character] = [Character]()
 4         for char in S.characters
 5         {
 6             arr.append(char)
 7         }       
 8         let len = S.count
 9         //声明数组
10         var ct:[Int] = [Int](repeating: 0,count: len + 1)
11         var x:Int = 0
12         for i in 0...len
13         {
14             ct[i] += x
15             if i < len && arr[i] == "1"
16             {
17                 x += 1
18             }
19         }
20         x = 0
21         for i in (0...len).reversed()
22         {
23            ct[i] += x
24             if i > 0 && arr[i - 1] == "0"
25             {
26                 x += 1
27             }            
28         }
29         var res = 999999999
30         for i in 0...len
31         {
32             res = min(res,ct[i])
33         }
34         return res       
35     }
36 }