Compilare: user.cpp: In function ‘void build(int, int, int)’: user.cpp:16:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&x); ^ user.cpp: In function ‘int main()’: user.cpp:65:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&n,&m); ^ user.cpp:68:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&x,&y); ^