View Compilation Error

0_0_33840921_28866.cpp:18:10: error: 'maxn' was not declared in this scope
 int trie[maxn*32][2];
          ^
0_0_33840921_28866.cpp:19:8: error: 'maxn' was not declared in this scope
 ll val[maxn*32];
        ^
0_0_33840921_28866.cpp: In function 'void init()':
0_0_33840921_28866.cpp:26:12: error: 'trie' was not declared in this scope
     memset(trie,0,sizeof(trie));
            ^
0_0_33840921_28866.cpp: In function 'void get_trie(ll)':
0_0_33840921_28866.cpp:35:13: error: 'trie' was not declared in this scope
         if(!trie[root][id])
             ^
0_0_33840921_28866.cpp:37:14: error: 'trie' was not declared in this scope
         root=trie[root][id];
              ^
0_0_33840921_28866.cpp:39:5: error: 'val' was not declared in this scope
     val[root]=u;
     ^
0_0_33840921_28866.cpp: In function 'll query(ll)':
0_0_33840921_28866.cpp:47:12: error: 'trie' was not declared in this scope
         if(trie[root][id^1])
            ^
0_0_33840921_28866.cpp:52:12: error: 'val' was not declared in this scope
     return val[root];
            ^