View Compilation Error

0_0_39539734_21478.cpp: In function 'void solve()':
0_0_39539734_21478.cpp:42:46: error: 't' was not declared in this scope
   42 |     for (int i = 0;i < m;i++) scanf("%d%d", &t.tree[i][0], &t.tree[i][1]);
      |                                              ^
0_0_39539734_21478.cpp: In lambda function:
0_0_39539734_21478.cpp:44:14: error: 't' was not declared in this scope; did you mean 'tr'?
   44 |         if (!t.tree[u][0] && !t.tree[u][1]) {
      |              ^
      |              tr
0_0_39539734_21478.cpp:50:17: error: 't' was not declared in this scope; did you mean 'tr'?
   50 |             if (t.tree[u][i]) self(self, t.tree[u][i], depth + 1);
      |                 ^
      |                 tr
0_0_39539734_21478.cpp: In function 'void solve()':
0_0_39539734_21478.cpp:54:5: error: 't' was not declared in this scope; did you mean 'tr'?
   54 |     t.build();
      |     ^
      |     tr