View Compilation Error

0_0_19215027_3926.cpp: In function 'int main()':
0_0_19215027_3926.cpp:10:36: error: 'scanf' was not declared in this scope
  while(scanf("%lf%lf%lf",&v,&m,&ang)!=-1)
                                    ^
0_0_19215027_3926.cpp:21:34: error: 'printf' was not declared in this scope
   if(dir<0) printf("%0.3lf\n",ans);
                                  ^
0_0_19215027_3926.cpp:22:42: error: 'printf' was not declared in this scope
   else  printf("%0.3lf\n",ans-sqrt(dir)/a);
                                          ^