View Compilation Error

0_0_37257223_9491.cpp: In function 'bool cmp(int, int)':
0_0_37257223_9491.cpp:5:8: error: 'i' was not declared in this scope
  if (a[i]-b[i])
        ^
0_0_37257223_9491.cpp:6:1: error: expected primary-expression before '}' token
 }
 ^
0_0_37257223_9491.cpp: In function 'int main()':
0_0_37257223_9491.cpp:9:2: error: 'cin' was not declared in this scope
  cin>>n;
  ^
0_0_37257223_9491.cpp:9:2: note: suggested alternative:
In file included from 0_0_37257223_9491.cpp:1:0:
GCC4.9.2/x86_64-w64-mingw32/include/c++/iostream:60:18: note:   'std::cin'
   extern istream cin;  /// Linked to standard input
                  ^