Valid stack pop sequence

valid stack pop sequence

In fact a very simple simulation.

Just try to pop as many elements as possible after each push.

class Solution {
public:
    bool validateStackSequences(vector<int>& pushed, vector<int>& popped) {
        stack<int> s;
        int j = 0;
        for (int i = 0; i < pushed.size(); i++) {
            s.push(pushed[i]);
            while (!s.empty() && s.top() == popped[j]) {
                s.pop();
                j++;
            }
        }
        return s.empty();
    }
};