View Compilation Error

0_0_18393101_5500.cpp: In function 'int RI()':
0_0_18393101_5500.cpp:111:50: error: 'getchar_unlocked' was not declared in this scope
     int  ret = 0, flag = 1,ip = getchar_unlocked();
                                                  ^
0_0_18393101_5500.cpp: In function 'int main()':
0_0_18393101_5500.cpp:255:24: error: 'M_PI' was not declared in this scope
             double ang=M_PI-aans;
                        ^