View Compilation Error

0_0_35712187_1076.cpp: In function 'void Prime()':
0_0_35712187_1076.cpp:10:36: error: 'memset' was not declared in this scope
  memset(isprime, 0, sizeof(isprime));
                                    ^
0_0_35712187_1076.cpp: In function 'int main()':
0_0_35712187_1076.cpp:48:27: error: 'memset' was not declared in this scope
    memset(arr,0,sizeof arr);
                           ^