View Compilation Error

0_0_32490297_11933.cpp: In function 'void init()':
0_0_32490297_11933.cpp:30:9: error: 'tree' was not declared in this scope
  memset(tree, 0, sizeof(tree));
         ^
0_0_32490297_11933.cpp: In function 'void insert(std::string)':
0_0_32490297_11933.cpp:40:8: error: 'tree' was not declared in this scope
   if (!tree[p].next[c])
        ^
0_0_32490297_11933.cpp:42:7: error: 'tree' was not declared in this scope
   p = tree[p].next[c];
       ^
0_0_32490297_11933.cpp:44:2: error: 'tree' was not declared in this scope
  tree[p].color = true;
  ^
0_0_32490297_11933.cpp: In function 'bool find(std::string)':
0_0_32490297_11933.cpp:53:7: error: 'tree' was not declared in this scope
   if (tree[p].color)
       ^
0_0_32490297_11933.cpp:55:7: error: 'tree' was not declared in this scope
   p = tree[p].next[c];
       ^