Compilare: user.cpp: In function ‘int main()’: user.cpp:42:13: warning: unused variable ‘x’ [-Wunused-variable] int n,m,x,y,i,cost,k; ^ user.cpp:42:15: warning: unused variable ‘y’ [-Wunused-variable] int n,m,x,y,i,cost,k; ^ user.cpp:40:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("apm.in","r",stdin); ^ user.cpp:41:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("apm.out","w",stdout); ^ user.cpp:43:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d",&n,&m); ^ user.cpp:45:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d",&v[i].u,&v[i].v,&v[i].c); ^