View Compilation Error

0_0_32786209_13820.cpp: In function 'int main()':
0_0_32786209_13820.cpp:37:44: error: 'arr' was not declared in this scope
         for(int i = 1; i <= n; i++) cin >> arr[i];
                                            ^
0_0_32786209_13820.cpp:38:14: error: 'arr' was not declared in this scope
         sort(arr + 1, arr + n + 1, cmp1);
              ^