View Compilation Error

0_0_26638837_15247.cpp:9:12: error: 'int exp [123]' redeclared as different kind of symbol
 int exp[123];
            ^
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_26638837_15247.cpp:2:
GCC4.9.2/x86_64-w64-mingw32/include/math.h:148:18: note: previous declaration 'double exp(double)'
   double __cdecl exp(double _X);
                  ^
0_0_26638837_15247.cpp: In function 'int main()':
0_0_26638837_15247.cpp:18:23: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
      scanf("%d",&exp[i]);
                       ^
0_0_26638837_15247.cpp:29:67: error: invalid types '<unresolved overloaded function type>[int]' for array subscript
                ans[i][u]=max(ans[i][u-1],ans[i-renn[j]][u-1]+exp[j]);
                                                                   ^