LeetCode:1441. 用栈操作构建数组

class Solution {
public:
    vector<string> buildArray(vector<int>& target, int n) {
        //对于每一个[0..n]中的数字，如果,它存在于target之中那么就push_back一个Push
        //否则push_back一个pop_back
        set<int>obj;
        for(int i=0;i<target.size();i++)
        {
            obj.insert(target[i]);
        }
        vector<string>res;
        for(int i=1;i<=*max_element(target.begin(),target.end());i++)
        {
            if(obj.count(i)==0)
            {
                res.push_back("Push");
                res.push_back("Pop");
            }
            else
            {
                res.push_back("Push");
            }
        }
        return res;
    }
};