Compilare: user.cpp: In function ‘int main()’: user.cpp:8:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tribute.in","r",stdin); ^ user.cpp:9:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tribute.out","w",stdout); ^ user.cpp:10:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&lin,&col); ^ user.cpp:13:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&vcc[i].x,&vcc[i].y); ^ user.cpp:37:14: warning: ‘poz1’ may be used uninitialized in this function [-Wmaybe-uninitialized] poz3=poz1+col; ^ user.cpp:36:13: warning: ‘poz’ may be used uninitialized in this function [-Wmaybe-uninitialized] poz2=poz+lin; ^