View Compilation Error

0_0_31456291_2565.cpp: In function 'int solve(int, int, int)':
0_0_31456291_2565.cpp:8:38: error: '__builrin_popcount' was not declared in this scope
     if(!n)return __builrin_popcount(y);
                                      ^
0_0_31456291_2565.cpp:9:40: error: 'niake_pair' was not declared in this scope
     auto pr=niake_pair(make_pair(x,y),n);
                                        ^