View Compilation Error

0_0_21397990_3303.cpp: In function 'int solve(int, int)':
0_0_21397990_3303.cpp:46:23: error: reference to 'next' is ambiguous
   if ((1<<k)<=n-st&&a[next[st][k]].y<=R)
                       ^
0_0_21397990_3303.cpp:9:5: note: candidates are: int next [100005][20]
 int next[N][20];
     ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_algobase.h:66:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:61,
                 from 0_0_21397990_3303.cpp:2:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_iterator_base_funcs.h:184:5: note:                 template<class _ForwardIterator> _ForwardIterator std::next(_ForwardIterator, typename std::iterator_traits<_Iter>::difference_type)
     next(_ForwardIterator __x, typename
     ^
0_0_21397990_3303.cpp: In function 'int main()':
0_0_21397990_3303.cpp:57:4: error: reference to 'next' is ambiguous
    next[i][0]=findx(a[i].y+1);//¼´Ô­À´µÄnext[i]
    ^
0_0_21397990_3303.cpp:9:5: note: candidates are: int next [100005][20]
 int next[N][20];
     ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_algobase.h:66:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:61,
                 from 0_0_21397990_3303.cpp:2:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_iterator_base_funcs.h:184:5: note:                 template<class _ForwardIterator> _ForwardIterator std::next(_ForwardIterator, typename std::iterator_traits<_Iter>::difference_type)
     next(_ForwardIterator __x, typename
     ^
0_0_21397990_3303.cpp:59:5: error: reference to 'next' is ambiguous
     next[i][j]=next[next[i][j-1]][j-1];
     ^
0_0_21397990_3303.cpp:9:5: note: candidates are: int next [100005][20]
 int next[N][20];
     ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_algobase.h:66:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:61,
                 from 0_0_21397990_3303.cpp:2:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_iterator_base_funcs.h:184:5: note:                 template<class _ForwardIterator> _ForwardIterator std::next(_ForwardIterator, typename std::iterator_traits<_Iter>::difference_type)
     next(_ForwardIterator __x, typename
     ^
0_0_21397990_3303.cpp:59:16: error: reference to 'next' is ambiguous
     next[i][j]=next[next[i][j-1]][j-1];
                ^
0_0_21397990_3303.cpp:9:5: note: candidates are: int next [100005][20]
 int next[N][20];
     ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_algobase.h:66:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:61,
                 from 0_0_21397990_3303.cpp:2:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_iterator_base_funcs.h:184:5: note:                 template<class _ForwardIterator> _ForwardIterator std::next(_ForwardIterator, typename std::iterator_traits<_Iter>::difference_type)
     next(_ForwardIterator __x, typename
     ^
0_0_21397990_3303.cpp:59:21: error: reference to 'next' is ambiguous
     next[i][j]=next[next[i][j-1]][j-1];
                     ^
0_0_21397990_3303.cpp:9:5: note: candidates are: int next [100005][20]
 int next[N][20];
     ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_algobase.h:66:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:61,
                 from 0_0_21397990_3303.cpp:2:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_iterator_base_funcs.h:184:5: note:                 template<class _ForwardIterator> _ForwardIterator std::next(_ForwardIterator, typename std::iterator_traits<_Iter>::difference_type)
     next(_ForwardIterator __x, typename
     ^