Compilare: user.cpp: In function ‘int main()’: user.cpp:15:15: warning: unused variable ‘j’ [-Wunused-variable] int m,x,y,j; ^ user.cpp:18:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&n,&m); ^ user.cpp:21:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&x,&y); ^ user.cpp:24:64: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d %d %d %d ", &startx, &starty, &stopx, &stopy); ^