View Compilation Error

0_0_29920243_29069.cpp: In function 'node multi(node, node)':
0_0_29920243_29069.cpp:13:35: error: 'memset' was not declared in this scope
     memset(tmp.v, 0, sizeof(tmp.v));
                                   ^
0_0_29920243_29069.cpp: In function 'node pow_mod(node, ll)':
0_0_29920243_29069.cpp:27:35: error: 'memset' was not declared in this scope
     memset(res.v, 0, sizeof(res.v));
                                   ^