题目链接：https://www.luogu.com.cn/problem/P5250
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <map>
using namespace std
;
int n
;
map
<int, int> h
;
int main(){
cin
>> n
;
while (n
-- ){
int a
, b
; cin
>> a
>> b
;
if (a
== 1){
if (h
.count(b
)) puts("Already Exist");
else h
[b
] = 1;
}
else {
if (h
.empty()) puts("Empty");
else if (h
.count(b
)){
h
.erase(b
);
cout
<< b
<< endl
;
}
else {
h
[b
] = 1;
auto it
= h
.find(b
);
auto it2
= it
;
it
++;
if (it2
== h
.begin()){
cout
<< it
->first
<< endl
;
h
.erase(it
);
}
else if (it
== h
.end()){
cout
<< (-- it2
)->first
<< endl
;
h
.erase(it2
);
}
else if (b
- (--it2
)->first
> it
->first
- b
){
cout
<< it
->first
<< endl
;
h
.erase(it
);
}
else {
cout
<< it2
->first
<< endl
;
h
.erase(it2
);
}
h
.erase(b
);
}
}
}
return 0;
}
