思路:模拟就完事
class Solution {
public:
bool validateStackSequences(vector<int>& pushed, vector<int>& popped) {
stack<int> c;
int idx=0;
for(int v:pushed){
c.push(v);
while(c.size()&&c.top()==popped[idx]){
c.pop();
idx++;
}
}
while(c.size()){
if(c.top()!=popped[idx]) return false;
c.pop();
idx++;
}
return true;
}
};