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0_0_30885525_17866.cpp:530:17: error: 'int log2 [8388608]' redeclared as different kind of symbol
 int log2[1 << 23];
                 ^
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++/x86_64-w64-mingw32/bits/stdc++.h:41,
                 from 0_0_30885525_17866.cpp:1:
GCC4.9.2/x86_64-w64-mingw32/include/math.h:638:25: note: previous declaration 'double log2(double)'
   extern double __cdecl log2 (double);
                         ^
0_0_30885525_17866.cpp: In function 'void initialize()':
0_0_30885525_17866.cpp:563:14: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
   log2[1 << i] = i;
              ^
0_0_30885525_17866.cpp:567:38: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
   pwr2[i] = pwr2[i - 1] + log2[i & -i];
                                      ^