/in/foo.cc: In function 'void solution()':
/in/foo.cc:61:9: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
         for (const auto& ele: keys) cout << ele << " "; cout << endl;
         ^~~
/in/foo.cc:61:57: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
         for (const auto& ele: keys) cout << ele << " "; cout << endl;
                                                         ^~~~