View Compilation Error

0_0_31914001_28271.cpp: In function 'int main()':
0_0_31914001_28271.cpp:26:39: error: 'memset' was not declared in this scope
         memset(scores,0,sizeof(scores));
                                       ^
0_0_31914001_28271.cpp:47:39: error: 'sort' was not declared in this scope
   sort(students, students + n, compare);
                                       ^