Compilare: user.cpp: In function ‘int main()’: user.cpp:4:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] int main(){freopen("unuzero.in","r",stdin);freopen("unuzero.out","w",stdout);scanf("%d%d%d",&n,&a,&b);z[0]=1;s[0]=1;for(int i=1;i<=n;++i){z[i]=z[i-1]+u[i-1];z[i]%=mod;if(i-a>=0){if(i-b-1>=0){u[i]=s[i-a]-s[i-b-1];}else{u[i]=s[i-a];}}if(u[i]<0) u[i]+=mod;u[i]%=mod;s[i]=s[i-1]+z[i];s[i]%=mod;}printf("%d",(z[n]+u[n]-1+((z[n]+u[n]-1)%mod<0))%mod);return 0;} ^ user.cpp:4:77: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] int main(){freopen("unuzero.in","r",stdin);freopen("unuzero.out","w",stdout);scanf("%d%d%d",&n,&a,&b);z[0]=1;s[0]=1;for(int i=1;i<=n;++i){z[i]=z[i-1]+u[i-1];z[i]%=mod;if(i-a>=0){if(i-b-1>=0){u[i]=s[i-a]-s[i-b-1];}else{u[i]=s[i-a];}}if(u[i]<0) u[i]+=mod;u[i]%=mod;s[i]=s[i-1]+z[i];s[i]%=mod;}printf("%d",(z[n]+u[n]-1+((z[n]+u[n]-1)%mod<0))%mod);return 0;} ^ user.cpp:4:102: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int main(){freopen("unuzero.in","r",stdin);freopen("unuzero.out","w",stdout);scanf("%d%d%d",&n,&a,&b);z[0]=1;s[0]=1;for(int i=1;i<=n;++i){z[i]=z[i-1]+u[i-1];z[i]%=mod;if(i-a>=0){if(i-b-1>=0){u[i]=s[i-a]-s[i-b-1];}else{u[i]=s[i-a];}}if(u[i]<0) u[i]+=mod;u[i]%=mod;s[i]=s[i-1]+z[i];s[i]%=mod;}printf("%d",(z[n]+u[n]-1+((z[n]+u[n]-1)%mod<0))%mod);return 0;} ^