foo.cpp: In function 'int main()':
foo.cpp:21:3: error: reference to 'hash' is ambiguous
   hash[a]++;
   ^
foo.cpp:5:23: note: candidates are: int hash [5]
 int p[50][50][50][50],hash[5],p1,p2,p3,p4,m,n,map[400];
                       ^
In file included from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\basic_string.h:3033:0,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\string:52,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\locale_classes.h:40,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\ios_base.h:41,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\ios:42,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\ostream:38,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\iostream:39,
                 from foo.cpp:1:
c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^
foo.cpp:24:15: error: reference to 'hash' is ambiguous
  for(p1=0;p1<=hash[1];p1++)
               ^
foo.cpp:5:23: note: candidates are: int hash [5]
 int p[50][50][50][50],hash[5],p1,p2,p3,p4,m,n,map[400];
                       ^
In file included from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\basic_string.h:3033:0,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\string:52,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\locale_classes.h:40,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\ios_base.h:41,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\ios:42,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\ostream:38,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\iostream:39,
                 from foo.cpp:1:
c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^
foo.cpp:25:15: error: reference to 'hash' is ambiguous
  for(p2=0;p2<=hash[2];p2++)
               ^
foo.cpp:5:23: note: candidates are: int hash [5]
 int p[50][50][50][50],hash[5],p1,p2,p3,p4,m,n,map[400];
                       ^
In file included from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\basic_string.h:3033:0,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\string:52,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\locale_classes.h:40,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\ios_base.h:41,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\ios:42,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\ostream:38,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\iostream:39,
                 from foo.cpp:1:
c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^
foo.cpp:26:15: error: reference to 'hash' is ambiguous
  for(p3=0;p3<=hash[3];p3++)
               ^
foo.cpp:5:23: note: candidates are: int hash [5]
 int p[50][50][50][50],hash[5],p1,p2,p3,p4,m,n,map[400];
                       ^
In file included from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\basic_string.h:3033:0,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\string:52,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\locale_classes.h:40,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\ios_base.h:41,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\ios:42,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\ostream:38,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\iostream:39,
                 from foo.cpp:1:
c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^
foo.cpp:27:1