View Compilation Error

0_0_39206290_25399.cpp:83:12: error: expected unqualified-id before ')' token
   83 |     BIT<T>() {}
      |            ^
0_0_39206290_25399.cpp:84:12: error: expected unqualified-id before 'int'
   84 |     BIT<T>(int _n) : n(_n) { memset(t, 0, sizeof(t)); }
      |            ^~~
0_0_39206290_25399.cpp:84:12: error: expected ')' before 'int'
   84 |     BIT<T>(int _n) : n(_n) { memset(t, 0, sizeof(t)); }
      |           ~^~~
      |            )
0_0_39206290_25399.cpp:85:12: error: expected unqualified-id before 'int'
   85 |     BIT<T>(int _n, T *a) : n(_n)
      |            ^~~
0_0_39206290_25399.cpp:85:12: error: expected ')' before 'int'
   85 |     BIT<T>(int _n, T *a) : n(_n)
      |           ~^~~
      |            )