Compilare: main.cpp: In function 'int main()': main.cpp:35:25: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&n); ^ main.cpp:37:44: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&v[i].x,&v[i].y); ^ main.cpp:24:78: warning: 'p4' may be used uninitialized in this function [-Wmaybe-uninitialized] return 1.0*modul((v[i].x-v[k].x)*(v[j].y-v[k].y) - (v[j].x-v[k].x)*(v[i].y-v[k].y))/2.0; ~~~~~^ main.cpp:33:20: note: 'p4' was declared here int i,p1,p2,p3,p4,dmax,j,xsol; ^~