leetcode栈--2、largest-rectangle-in-histogram（直方图最大面积）

 1 class Solution {
 2 public:
 3     int largestRectangleArea(vector<int> &height) {
 4         int result = 0;
 5         stack<int> s;
 6         int n = height.size();
 7         for(int i=0;i<n;i++)
 8         {
 9             if(s.empty() || height[i] >= s.top())
10             {
11                 s.push(height[i]);
12             }
13             else
14             {
15                 int count = 0;
16                 while(!s.empty() && s.top() > height[i])
17                 {
18                     count ++;
19                     result = max(result, s.top()*count);
20                     s.pop();
21                 }
22                 while(count --)//弹出的位置用当前值替换
23                     s.push(height[i]);
24                 s.push(height[i]);//将当前值放入栈中
25             }
26         }
27         int count = 1;
28         while(!s.empty())
29         {
30             result = max(result, s.top()*count);
31             s.pop();
32             count ++;
33         }
34         return result;
35     }
36 };