View Compilation Error

0_0_22225566_2168.cpp: In function 'int main()':
0_0_22225566_2168.cpp:14:35: error: 'memset' was not declared in this scope
           memset(num,0,sizeof(num));
                                   ^
0_0_22225566_2168.cpp:29:29: error: 'sort' was not declared in this scope
           sort(num+1,num+1+n);
                             ^