Leetcode-946 验证栈序列(Validate Stack Sequences)

 1 class Solution
 2 {
 3     public:
 4         bool validateStackSequences(vector<int>& pushed, vector<int>& popped)
 5         {
 6             stack<int> s;
 7             int pushedEnd = -1;
 8             for(int i = 0;i < popped.size();i ++)
 9             {
10                 if(s.empty()||s.top()!=popped[i])
11                 {
12                     pushedEnd ++;
13                     for(;pushedEnd < pushed.size()
14                     &&  pushed[pushedEnd]!=popped[i];pushedEnd ++)
15                     {
16                         s.push(pushed[pushedEnd]);
17                     }
18                     if(pushedEnd==pushed.size())
19                         return false;
20                 }
21                 else if(s.top()==popped[i])
22                     s.pop();
23             }
24             return true;
25         }
26 };