Compilare: user.cpp: In function ‘int main()’: user.cpp:49:9: warning: unused variable ‘st’ [-Wunused-variable] int st = 1, dr = cost; ^ user.cpp:49:17: warning: unused variable ‘dr’ [-Wunused-variable] int st = 1, dr = cost; ^ user.cpp:39:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tarabe.in","r",stdin); ^ user.cpp:40:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tarabe.out","w",stdout); ^ user.cpp:41:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:43:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&b[i],&a[i]); ^