View Compilation Error

0_0_23945499_29078.cpp: In function 'void init(int)':
0_0_23945499_29078.cpp:25:47: error: 'memset' was not declared in this scope
  memset(trie[x].next, -1, sizeof(trie[x].next));
                                               ^
0_0_23945499_29078.cpp: In function 'int main()':
0_0_23945499_29078.cpp:139:25: error: 'strlen' was not declared in this scope
    build(str, strlen(str), i, false);
                         ^
0_0_23945499_29078.cpp:144:25: error: 'strlen' was not declared in this scope
    build(str, strlen(str), 0, true);
                         ^