Compilare: user.cpp: In function ‘int main()’: user.cpp:17:12: warning: unused variable ‘y’ [-Wunused-variable] double y,x3,y3,x4,y4,delta; ^ user.cpp:20:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d " ,&t); ^ user.cpp:23:76: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%lf %lf %lf %lf %lf %lf " ,&A.x,&A.y,&A.r,&B.x,&B.y,&B.r); ^