View Compilation Error

0_0_26489672_26044.cpp: In function 'void build(int, int, int)':
0_0_26489672_26044.cpp:20:6: error: 'nth_element' was not declared in this scope
     });
      ^
0_0_26489672_26044.cpp: In function 'int main()':
0_0_26489672_26044.cpp:1:36: error: 'stdin' was not declared in this scope
 #define FRER() freopen("i.txt","r",stdin)
                                    ^
0_0_26489672_26044.cpp:32:5: note: in expansion of macro 'FRER'
     FRER();
     ^
0_0_26489672_26044.cpp:1:41: error: 'freopen' was not declared in this scope
 #define FRER() freopen("i.txt","r",stdin)
                                         ^
0_0_26489672_26044.cpp:32:5: note: in expansion of macro 'FRER'
     FRER();
     ^
0_0_26489672_26044.cpp:34:18: error: 'scanf' was not declared in this scope
     scanf("%d",&T);
                  ^