/in/foo.cc: In function 'int main()':
/in/foo.cc:6:2: error: 'vector' was not declared in this scope
  vector<int> nums;
  ^~~~~~
/in/foo.cc:6:9: error: expected primary-expression before 'int'
  vector<int> nums;
         ^~~
/in/foo.cc:11:3: error: 'nums' was not declared in this scope
   nums.push_back(in);
   ^~~~
/in/foo.cc:13:9: error: expected primary-expression before 'bool'
  vector<bool> dic(20001);
         ^~~~
/in/foo.cc:17:4: error: 'dic' was not declared in this scope
    dic[i+j] = 1;
    ^~~
/in/foo.cc:23:13: error: 'nums' was not declared in this scope
  for(auto i:nums){
             ^~~~
/in/foo.cc:24:7: error: 'dic' was not declared in this scope
    if(dic[i]){
       ^~~