Compilare: user.c:15:1: warning: return type defaults to ‘int’ [enabled by default] printmare(mare m){int i;if(!m.len)return 0;printf("%d",m.a[m.len-1]);for(i=m.len-1;i--;)printf(MAREPRINTFORMAT,m.a[i]);} ^ user.c:21:1: warning: return type defaults to ‘int’ [enabled by default] main(){freopen("perm.in","r",stdin);freopen("perm.out","w",stdout); ^ user.c: In function ‘printmare’: user.c:15:1: warning: control reaches end of non-void function [-Wreturn-type] printmare(mare m){int i;if(!m.len)return 0;printf("%d",m.a[m.len-1]);for(i=m.len-1;i--;)printf(MAREPRINTFORMAT,m.a[i]);} ^ user.c: In function ‘main’: user.c:21:15: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] main(){freopen("perm.in","r",stdin);freopen("perm.out","w",stdout); ^ user.c:21:44: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] main(){freopen("perm.in","r",stdin);freopen("perm.out","w",stdout); ^ user.c:22:6: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&k);mare tempm; ^