foo.cpp:21:26: error: 'int floor [110]' redeclared as different kind of symbol
 int used[maxn],floor[maxn];
                          ^
In file included from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/cmath:44:0,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/random:38,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/bits/stl_algo.h:66,
                 from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/algorithm:62,
                 from foo.cpp:3:
C:/TDM-GCC-32/include/math.h:159:24: note: previous declaration 'double floor(double)'
 _CRTIMP double __cdecl floor (double);
                        ^
foo.cpp: In function 'void bfs(int, int)':
foo.cpp:25:30: error: ISO C++ forbids applying 'sizeof' to an expression of function type [-fpermissive]
  memset(floor,-1,sizeof(floor));
                              ^
foo.cpp:25:31: error: cannot resolve overloaded function 'floor' based on conversion to type 'void*'
  memset(floor,-1,sizeof(floor));
                               ^
foo.cpp:26:9: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
  floor[s]=0;q.push(s);
         ^
foo.cpp:30:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i=0;i<pic[thi].size();i++)
                 ^
foo.cpp:34:18: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
    if (floor[e.to]!=-1) continue;
                  ^
foo.cpp:35:14: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
    floor[e.to]=floor[thi]+1;
              ^
foo.cpp:35:25: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
    floor[e.to]=floor[thi]+1;
                         ^
foo.cpp: In function 'int dfs(int, int, int)':
foo.cpp:44:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int &i=used[s];i<pic[s].size();i++)
                       ^
foo.cpp:48:17: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
   if (floor[e.to]<=floor[s]) continue;
                 ^
foo.cpp:48:27: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
   if (floor[e.to]<=floor[s]) continue;
                           ^
foo.cpp: In function 'int maxflow(int, int)':
foo.cpp:65:14: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
   if (floor[t]==-1) break;
              ^