/in/foo.cc: In function 'int main()':
/in/foo.cc:17:5: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
     while (cin >> a[++n]); n--;
     ^~~~~
/in/foo.cc:17:28: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'while'
     while (cin >> a[++n]); n--;
                            ^