Compilare: user.cpp: In function ‘int main()’: user.cpp:33:7: warning: unused variable ‘j’ [-Wunused-variable] int i,j,n,m,a,b,c,cost=0,N=0; ^ user.cpp:34:6: warning: unused variable ‘ok’ [-Wunused-variable] bool ok=true; ^ user.cpp:31:29: 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:32:30: 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:35:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:38:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&a,&b,&c); ^