Compilare: main.cpp: In function 'int main()': main.cpp:2:108: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] using namespace std;char v[1000000],st[1000000];int main(){int n,m,c,i,x=1;freopen("trompeta.in","r",stdin);freopen("trompeta.out","w",stdout);scanf("%d%d\n", &n, &m);for (i=1;i<=n;i++)v[i]=fgetc(stdin);st[1]=v[1];c=n-m;for (i=2;i<=n;st[++x]=v[i],i++)while (c!=0 && x!=0 && v[i]-'0'>st[x]-'0')c--,x--;printf("%s", st+1);return 0;} ^ main.cpp:2:143: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] using namespace std;char v[1000000],st[1000000];int main(){int n,m,c,i,x=1;freopen("trompeta.in","r",stdin);freopen("trompeta.out","w",stdout);scanf("%d%d\n", &n, &m);for (i=1;i<=n;i++)v[i]=fgetc(stdin);st[1]=v[1];c=n-m;for (i=2;i<=n;st[++x]=v[i],i++)while (c!=0 && x!=0 && v[i]-'0'>st[x]-'0')c--,x--;printf("%s", st+1);return 0;} ^ main.cpp:2:167: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] using namespace std;char v[1000000],st[1000000];int main(){int n,m,c,i,x=1;freopen("trompeta.in","r",stdin);freopen("trompeta.out","w",stdout);scanf("%d%d\n", &n, &m);for (i=1;i<=n;i++)v[i]=fgetc(stdin);st[1]=v[1];c=n-m;for (i=2;i<=n;st[++x]=v[i],i++)while (c!=0 && x!=0 && v[i]-'0'>st[x]-'0')c--,x--;printf("%s", st+1);return 0;} ^