Compilare: user.cpp: In function ‘bool slv(int, int, int, int)’: user.cpp:32:61: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return ( lst1.size() + lst2.size() + lst3.size() == x + y ); ^ user.cpp: In function ‘int main()’: user.cpp:119:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 0; i < lst3.size(); i ++ ) ^ user.cpp:120:56: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] mrk[lst3[i]] = ( i < j - lst1.size() ) ? 1 : 2; ^