Compilare: user.cpp: In function ‘void build(int, int, int)’: user.cpp:20:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i<v[2*nod].size() && j<v[2*nod+1].size()){ ^ user.cpp:20:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i<v[2*nod].size() && j<v[2*nod+1].size()){ ^ user.cpp:30:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i<v[2*nod].size()){ ^ user.cpp:34:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (j<v[2*nod+1].size()){ ^ user.cpp: In function ‘int main()’: user.cpp:93:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&n); ^ user.cpp:95:53: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&a[i].first,&a[i].second); ^ user.cpp:99:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&m); ^ user.cpp:101:48: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d%d%d",&x1,&y1,&x2,&y2); ^