Main.cc: In function ‘int main()’:
Main.cc:14:12: error: ‘u’ was not declared in this scope
memset ( u , 0 , sizeof ( u ) ) ;
^
Main.cc:17:18: error: ‘num’ was not declared in this scope
if ( 1 << i & num )
^~~
Main.cc:17:18: note: suggested alternative: ‘sum’
if ( 1 << i & num )
^~~
sum