/in/foo.cc: In function 'int main()':
/in/foo.cc:6:26: warning: variable 'ming' set but not used [-Wunused-but-set-variable]
  double temp, a[100000], ming = 0, hong = 0;
                          ^~~~
/in/foo.cc:6:36: warning: variable 'hong' set but not used [-Wunused-but-set-variable]
  double temp, a[100000], ming = 0, hong = 0;
                                    ^~~~
/in/foo.cc:16:2: warning: 'temp' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if (a[0] == temp || a[n - 1] == temp)
  ^~