foo.cc: In function 'int main()':
foo.cc:5:9: error: 'set' was not declared in this scope
    5 |         set<int> sum;
      |         ^~~
foo.cc:2:1: note: 'std::set' is defined in header '<set>'; did you forget to '#include <set>'?
    1 | #include<iostream>
  +++ |+#include <set>
    2 | using namespace  std;
foo.cc:5:13: error: expected primary-expression before 'int'
    5 |         set<int> sum;
      |             ^~~
foo.cc:9:25: error: 'sum' was not declared in this scope
    9 |                         sum.insert(j);
      |                         ^~~
foo.cc:11:15: error: 'sum' was not declared in this scope
   11 |         cout<<sum.size();
      |               ^~~

正在同步测试数据，请稍后
[Hydro](https://hydro.ac)提供评测服务