典型的利用指针加减模拟删除和增加文档
#include<bits/stdc++.h>
using namespace std;
int top=1;
bool a[100010];
int main()
{
int n;
cin>>n;
string s;
int id;
for(int i=1;i<=n;i++)
{
cin>>s;
if(s=="New")
{
a[top]=true;
cout<<top<<endl;
while(a[top]==true)
{
top++;
}
}
else
{
cin>>id;
if(a[id]==true)
{
cout<<"Successful"<<endl;
a[id]=false;
if(id<top)top=id;
}
else cout<<"Failed"<<endl;
}
}
return 0;
}