/in/foo.cc: In function 'int main()':
/in/foo.cc:25:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for(int i=1;i<=n;i++)
     ^~~
/in/foo.cc:28:2: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
  for(int i=n;i>=1;i--)
  ^~~
/in/foo.cc:18:11: warning: variable 'k' set but not used [-Wunused-but-set-variable]
     int n,k;
           ^