View Compilation Error

0_0_19436229_12798.cpp: In member function 'void TRIE::init()':
0_0_19436229_12798.cpp:16:38: error: 'memset' was not declared in this scope
 #define mem(p,c) memset(p,c,sizeof(p))
                                      ^
0_0_19436229_12798.cpp:49:24: note: in expansion of macro 'mem'
 void init(){pos=1;cn=0;mem(tr[0].p,0);tr[0].s=0;}
                        ^
0_0_19436229_12798.cpp: In member function 'void TRIE::insert(int)':
0_0_19436229_12798.cpp:52:17: error: 'strlen' was not declared in this scope
 int len=strlen(s),t=0;
                 ^
0_0_19436229_12798.cpp:57:7: error: 't' was not declared in this scope
 if(tr[t].p[s[x]-'a']){
       ^
0_0_19436229_12798.cpp:16:38: error: 'memset' was not declared in this scope
 #define mem(p,c) memset(p,c,sizeof(p))
                                      ^
0_0_19436229_12798.cpp:68:1: note: in expansion of macro 'mem'
 mem(tr[t].p,0);
 ^