StoneWall【★★★★★】

 1         /// <summary>
 2         /// Solution
 3         /// 100/100
 4         /// </summary>
 5         /// <param name="H"></param>
 6         /// <returns></returns>
 7         public int solution(int[] H)
 8         {
 9             int numBlocks = H.Length;
10             bool isDecreasing = false;
11             Stack<int> stack = new Stack<int>();
12             for (int i = 1; i < H.Length; i++)
13             {
14                 if (H[i] == H[i - 1])
15                 {
16                     numBlocks--;
17                     isDecreasing = false;
18                 }
19                 else if (H[i] > H[i - 1])
20                 {
21                     stack.Push(H[i-1]);
22                     isDecreasing = false;
23                 }
24                 else
25                 {
26                     isDecreasing = true;
27                 }
28 
29                 if (isDecreasing == true)
30                 {
31                     while(stack.Count != 0 && H[i] < stack.Peek())
32                     {
33                         stack.Pop();
34                     }
35                     if (stack.Count != 0 && H[i] == stack.Peek())
36                     {
37                         numBlocks--;
38                     }
39                 }
40             }
41             return numBlocks;
42         }