Compilare: user.cpp: In function ‘int main()’: user.cpp:51:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int j = 0; j < lst[i].size(); j ++ ) { ^ user.cpp:56:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] int r = ( j == lst[i].size() - 1 ) ? n : lst[i][j + 1] - 1; ^ user.cpp:67:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int j = 0; j < lst[i].size(); j ++ ) { ^