View Compilation Error

0_0_16974717_12739.cpp: In function 'int main()':
0_0_16974717_12739.cpp:19:45: error: 'memset' was not declared in this scope
            memset ( bst, 0 , sizeof ( bst ) );
                                             ^
0_0_16974717_12739.cpp:20:17: error: 'i' was not declared in this scope
            for (i = 1; i <= N; ++ i )
                 ^