View Compilation Error

0_0_14510025_18104.cpp: In function 'void work()':
0_0_14510025_18104.cpp:33:33: error: 'sort' was not declared in this scope
   sort(e[i].begin() , e[i].end());
                                 ^
0_0_14510025_18104.cpp:48:59: error: 'upper_bound' was not declared in this scope
   vpi = upper_bound(e[l].begin() , e[l].end() , pii(r , 0));
                                                           ^