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

class Solution
{
    public:
        bool validateStackSequences(vector<int>& pushed, vector<int>& popped)
        {
            stack<int> s;
            int pushedEnd = -1;
            for(int i = 0;i < popped.size();i ++)
            {
                if(s.empty()||s.top()!=popped[i])
                {
                    pushedEnd ++;
                    for(;pushedEnd < pushed.size()
                    &&  pushed[pushedEnd]!=popped[i];pushedEnd ++)
                    {
                        s.push(pushed[pushedEnd]);
                    }
                    if(pushedEnd==pushed.size())
                        return false;
                }
                else if(s.top()==popped[i])
                    s.pop();
            }
            return true;
        }
};