Compilare: user.cpp: In function ‘int main()’: user.cpp:105:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < vertical_intervals.size() && vertical_intervals[i].x < 0) { ^ user.cpp:109:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < vertical_intervals.size() && vertical_intervals[i].x <= m-dx) { ^ user.cpp:115:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j < vertical_intervals.size() && vertical_intervals[j].x == vertical_intervals[j-1].x); ^ user.cpp:127:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < vertical_intervals.size() && vertical_intervals[i].x == vertical_intervals[i-1].x); ^