View Compilation Error

0_0_21485059_14591.cpp: In function 'void init()':
0_0_21485059_14591.cpp:12:39: error: 'memset' was not declared in this scope
     memset(isprime, 1, sizeof(isprime));
                                       ^
0_0_21485059_14591.cpp: In function 'int main()':
0_0_21485059_14591.cpp:47:19: error: 'scanf' was not declared in this scope
     scanf("%d", &T);
                   ^
0_0_21485059_14591.cpp:68:29: error: 'printf' was not declared in this scope
         printf("%lld\n", ret);
                             ^