View Compilation Error

0_0_37150549_9640.cpp: In function 'int main()':
0_0_37150549_9640.cpp:6:33: error: 'scanf' was not declared in this scope
     while (scanf("%d %d", &n, &m) != EOF)
                                 ^
0_0_37150549_9640.cpp:6:38: error: 'EOF' was not declared in this scope
     while (scanf("%d %d", &n, &m) != EOF)
                                      ^
0_0_37150549_9640.cpp:38:67: error: 'printf' was not declared in this scope
         for (i = 0; i < n - 1; i++) printf("%.2f ", average_stu[i]);
                                                                   ^
0_0_37150549_9640.cpp:39:44: error: 'printf' was not declared in this scope
         printf("%.2f\n", average_stu[n - 1]);
                                            ^