View Compilation Error

0_0_22048547_4745.cpp:22:11: error: no matching function for call to 'NNN::NNN()'
 NNN node[M],*POW,*last;
           ^
0_0_22048547_4745.cpp:22:11: note: candidates are:
0_0_22048547_4745.cpp:14:5: note: NNN::NNN(int)
     NNN(int _len)
     ^
0_0_22048547_4745.cpp:14:5: note:   candidate expects 1 argument, 0 provided
0_0_22048547_4745.cpp:10:8: note: constexpr NNN::NNN(const NNN&)
 struct NNN
        ^
0_0_22048547_4745.cpp:10:8: note:   candidate expects 1 argument, 0 provided
0_0_22048547_4745.cpp:10:8: note: constexpr NNN::NNN(NNN&&)
0_0_22048547_4745.cpp:10:8: note:   candidate expects 1 argument, 0 provided