Compilare: user.cpp: In function ‘bool Cmp(Edge, Edge)’: user.cpp:48:9: warning: unused variable ‘semn1’ [-Wunused-variable] int semn1,semn2; ^ user.cpp:48:15: warning: unused variable ‘semn2’ [-Wunused-variable] int semn1,semn2; ^ user.cpp: In function ‘int main()’: user.cpp:68:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("lazy.in","r",stdin); ^ user.cpp:69:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("lazy.out","w",stdout); ^ user.cpp:70:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n,&m); ^ user.cpp:73:65: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%lld%lld", &a[i].x,&a[i].y,&a[i].c1,&a[i].c2); ^