Compilare: user.cpp: In function ‘int main()’: user.cpp:4:11: warning: unused variable ‘first’ [-Wunused-variable] #define x first ^ user.cpp:29:15: note: in expansion of macro ‘x’ int i,N,M,x,y,sgn2,idx,sgn,vf=0; ^ user.cpp:5:11: warning: unused variable ‘second’ [-Wunused-variable] #define y second ^ user.cpp:29:17: note: in expansion of macro ‘y’ int i,N,M,x,y,sgn2,idx,sgn,vf=0; ^ user.cpp:32:30: 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:33:64: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i = 1; i <= N; ++i) fscanf(fin,"%d %d",&v[i].x,&v[i].y); ^ user.cpp:34:65: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i = 1; i <= M; ++i) fscanf(fin,"%d",&a[i].x), a[i].y = i; ^