View Compilation Error

0_0_19979870_21836.cpp:7:19: error: 'int log [610]' redeclared as different kind of symbol
 int N, M, log[maxn];
                   ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/cmath:44:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/random:38,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_algo.h:66,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:62,
                 from 0_0_19979870_21836.cpp:4:
GCC4.9.2/x86_64-w64-mingw32/include/math.h:149:18: note: previous declaration 'double log(double)'
   double __cdecl log(double _X);
                  ^
0_0_19979870_21836.cpp: In function 'int queryst(int, int)':
0_0_19979870_21836.cpp:21:21: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
  int len = log[r-l+1];
                     ^
0_0_19979870_21836.cpp: In function 'int main()':
0_0_19979870_21836.cpp:68:33: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
   l += ((1<<l) <= (i>>1)), log[i] = l;
                                 ^