View Compilation Error

0_0_30567615_20964.cpp: In function 'void primes()':
0_0_30567615_20964.cpp:22:31: error: 'memset' was not declared in this scope
  memset(prime, 1, sizeof prime);
                               ^
0_0_30567615_20964.cpp: In function 'int* add(int*, int*)':
0_0_30567615_20964.cpp:40:28: error: 'memset' was not declared in this scope
  memset(ans, 0, sizeof(ans));
                            ^
0_0_30567615_20964.cpp: In function 'int main()':
0_0_30567615_20964.cpp:74:27: error: 'memset' was not declared in this scope
   memset(x1, 0, sizeof(x1));
                           ^