View Compilation Error

0_0_36649279_8526.cpp: In function 'int main()':
0_0_36649279_8526.cpp:25:27: error: 'N' was not declared in this scope
     for (int nn = 1; nn < N; nn *= 10) {
                           ^
0_0_36649279_8526.cpp:29:5: error: 'arr' was not declared in this scope
     arr[F + i] = arr[i] + j;
     ^
0_0_36649279_8526.cpp:54:53: error: invalid operands of types 'LL {aka long long int}' and '<unresolved overloaded function type>' to binary 'operator*'
                 else minx = _a * M[j].back() * M[j].back + _b * M[j].back();
                                                     ^