View Compilation Error

0_0_20119516_22120.cpp: In member function 'void trie::query(char*)':
0_0_20119516_22120.cpp:100:13: error: 'used' was not declared in this scope
         mes(used,false);
             ^
0_0_20119516_22120.cpp:22:26: note: in definition of macro 'mes'
 #define mes(x, m) memset(x, m, sizeof(x))
                          ^