View Compilation Error

1_868_3151_29972.cpp: In function 'int main()':
1_868_3151_29972.cpp:18:24: error: 'memset' was not declared in this scope
   memset(c, 0, sizeof c);
                        ^
1_868_3151_29972.cpp:23:21: error: 'pow' was not declared in this scope
   q = (int)(pow(n, 4));
                     ^