View Compilation Error

0_0_38420415_13801.cpp: In function 'int main()':
0_0_38420415_13801.cpp:12:30: error: 'n' was not declared in this scope
         for ( int i = 0; i < n; i++ )
                              ^
0_0_38420415_13801.cpp:15:13: error: 'ans' was not declared in this scope
             ans += abs ( a[i] - p );
             ^
0_0_38420415_13801.cpp:15:33: error: 'p' was not declared in this scope
             ans += abs ( a[i] - p );
                                 ^
0_0_38420415_13801.cpp:17:23: error: 'ans' was not declared in this scope
         printf("%d\n",ans);
                       ^