Considérez trois ensembles A, Bet Cchacun contenant des nentiers. De cela, nous pouvons faire l'ensemble

S_n = {a * b + c | a in A, b in B, c in C}.

Étant donné un n, il existe une ou plusieurs tailles minimales S_nqui dépendent des ensembles A,B and Cchoisis.

Les ensembles peuvent contenir n'importe quel nentier distinct (positif, zéro ou négatif). Il n'est pas nécessaire qu'ils soient des entiers consécutifs ou que les ensembles soient égaux entre eux par exemple. A = {-1, 0, 5, 10, 27}, B = {2, 5, 6, 10, 14} and C = {-23, 2, 100, 1000,10000}est acceptable (mais pas une bonne idée) par exemple.

Tâche

La tâche consiste à écrire du code pour trouver le plus petit ensemble S_npossible pour chacun nde 1à 20.

Pour chacun nde 1à 20votre code devrait sortir le choisi A, Bet Cavec la taille résultante deS_n

But

Votre score sera la somme des tailles de celles que S_nvous créez. C'est-à-dire que ce sera une somme de vingt chiffres.

Plus le score est bas, mieux c'est.

Exemples

Si A = B = C = {1, 2, 3, 4}alors S_4 = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20}qui est de taille 19.

Ce n'est cependant nullement optimal. Par exemple, A = B = C = {-1, 0, 1, 2}donne S_4 = {0, 1, 2, 3, 4, 5, 6, -1, -3, -2}ce qui est de taille 10.

Timings

Comme je devrai exécuter votre code pour vérifier la sortie, assurez-vous qu'il ne faut pas plus de 30 minutes et 4 Go de RAM pour fonctionner sur un bureau normal.

Remarques

Votre code doit réellement calculer la sortie. Vous n'êtes pas autorisé à coder en dur les réponses précalculées dans votre code.

Rust, score 1412 1411

src/main.rs

extern crate gmp;

use std::collections::BinaryHeap;
use std::collections::hash_map::{HashMap, Entry};
use gmp::mpz::Mpz;

fn visit(
    queue: &mut BinaryHeap<(i32, i32, i32, Mpz, Mpz)>,
    visited: &mut HashMap<(i32, Mpz), i32>,
    score: i32,
    h: i32,
    k: i32,
    d: Mpz,
    c: Mpz,
) {
    match visited.entry((k, d.clone())) {
        Entry::Occupied(mut e) => {
            if *e.get() < score {
                e.insert(score);
                queue.push((score, h, k, d, c));
            }
        }
        Entry::Vacant(e) => {
            e.insert(score);
            queue.push((score, h, k, d, c));
        }
    }
}

fn main() {
    let mut total = 0;
    for n in 1..21 {
        let a_range = n / 2 - n + 1..n / 2 + 1;
        let min_ab = a_range.start * (a_range.end - 1);
        let mut ab = Mpz::zero();
        for a in a_range.clone() {
            for b in a_range.clone() {
                ab.setbit((a * b - min_ab) as usize);
            }
        }

        let heuristic = |k: i32, d: &Mpz| if k == n {
            0
        } else {
            k + 1 - n -
                (0..d.bit_length())
                    .map(|i| (&ab & !(d >> i)).popcount())
                    .min()
                    .unwrap() as i32
        };

        let mut queue = BinaryHeap::new();
        let mut visited = HashMap::new();

        let (k1, d1) = (0, Mpz::zero());
        let h1 = heuristic(k1, &d1);
        visit(&mut queue, &mut visited, h1, h1, k1, d1, Mpz::zero());
        while let Some((score, h, k, d, c)) = queue.pop() {
            if k == n {
                println!("n={} |S|={}", n, -score);
                println!("  A={:?}", a_range.clone().collect::<Vec<_>>());
                println!("  B={:?}", a_range.clone().collect::<Vec<_>>());
                println!(
                    "  C={:?}",
                    (0..c.bit_length())
                        .filter(|&i| c.tstbit(c.bit_length() - 1 - i))
                        .collect::<Vec<_>>()
                );
                total += -score;
                break;
            }

            let kd = (k, d);
            if score < visited[&kd] {
                continue;
            }
            let (k, d) = kd;

            let (k1, d1) = (k, &d >> 1);
            let h1 = heuristic(k1, &d1);
            visit(
                &mut queue,
                &mut visited,
                score - h + h1,
                h1,
                k1,
                d1,
                &c << 1,
            );

            let (k1, d1) = (k + 1, (&d | &ab) >> 1);
            let h1 = heuristic(k1, &d1);
            visit(
                &mut queue,
                &mut visited,
                score - h - (&ab & !&d).popcount() as i32 + h1,
                h1,
                k1,
                d1,
                &c << 1 | Mpz::one(),
            );
        }
    }

    println!("total={}", total);
}

Cargo.toml

[package]
name = "small"
version = "0.1.0"
authors = ["Anders Kaseorg <[email protected]>"]

[dependencies]
rust-gmp = "0.5.0"

Compilez et exécutez avec cargo run --release.

Production

n=1 |S|=1
  A=[0]
  B=[0]
  C=[0]
n=2 |S|=3
  A=[0, 1]
  B=[0, 1]
  C=[0, 1]
n=3 |S|=5
  A=[-1, 0, 1]
  B=[-1, 0, 1]
  C=[0, 1, 2]
n=4 |S|=10
  A=[-1, 0, 1, 2]
  B=[-1, 0, 1, 2]
  C=[0, 1, 2, 3]
n=5 |S|=13
  A=[-2, -1, 0, 1, 2]
  B=[-2, -1, 0, 1, 2]
  C=[0, 1, 2, 3, 4]
n=6 |S|=21
  A=[-2, -1, 0, 1, 2, 3]
  B=[-2, -1, 0, 1, 2, 3]
  C=[0, 2, 3, 4, 5, 6]
n=7 |S|=25
  A=[-3, -2, -1, 0, 1, 2, 3]
  B=[-3, -2, -1, 0, 1, 2, 3]
  C=[0, 2, 3, 5, 6, 7, 8]
n=8 |S|=35
  A=[-3, -2, -1, 0, 1, 2, 3, 4]
  B=[-3, -2, -1, 0, 1, 2, 3, 4]
  C=[0, 3, 4, 6, 7, 8, 10, 11]
n=9 |S|=39
  A=[-4, -3, -2, -1, 0, 1, 2, 3, 4]
  B=[-4, -3, -2, -1, 0, 1, 2, 3, 4]
  C=[0, 3, 4, 6, 7, 8, 10, 11, 14]
n=10 |S|=53
  A=[-4, -3, -2, -1, 0, 1, 2, 3, 4, 5]
  B=[-4, -3, -2, -1, 0, 1, 2, 3, 4, 5]
  C=[0, 1, 4, 5, 6, 9, 10, 11, 14, 15]
n=11 |S|=58
  A=[-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5]
  B=[-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5]
  C=[0, 1, 4, 5, 6, 9, 10, 11, 14, 15, 19]
n=12 |S|=74
  A=[-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6]
  B=[-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6]
  C=[0, 4, 5, 6, 9, 10, 11, 12, 15, 16, 17, 21]
n=13 |S|=80
  A=[-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6]
  B=[-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6]
  C=[0, 4, 5, 6, 9, 10, 11, 12, 15, 16, 17, 21, 22]
n=14 |S|=100
  A=[-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7]
  B=[-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7]
  C=[0, 1, 6, 7, 8, 12, 13, 14, 15, 19, 20, 21, 26, 27]
n=15 |S|=106
  A=[-7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7]
  B=[-7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7]
  C=[0, 5, 6, 7, 11, 12, 13, 14, 18, 19, 20, 21, 25, 26, 27]
n=16 |S|=128
  A=[-7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8]
  B=[-7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8]
  C=[0, 6, 7, 8, 13, 14, 15, 16, 20, 21, 22, 23, 28, 29, 30, 36]
n=17 |S|=135
  A=[-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8]
  B=[-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8]
  C=[0, 6, 7, 8, 13, 14, 15, 16, 20, 21, 22, 23, 28, 29, 30, 36, 44]
n=18 |S|=161
  A=[-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
  B=[-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
  C=[0, 7, 8, 9, 15, 16, 17, 18, 23, 24, 25, 26, 27, 32, 33, 34, 35, 41]
n=19 |S|=167
  A=[-9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
  B=[-9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
  C=[0, 7, 8, 9, 15, 16, 17, 18, 23, 24, 25, 26, 27, 32, 33, 34, 35, 41, 42]
n=20 |S|=197
  A=[-9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
  B=[-9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
  C=[0, 1, 8, 9, 10, 11, 17, 18, 19, 20, 21, 26, 27, 28, 29, 30, 36, 37, 38, 46]
total=1411

Sur mon ordinateur portable, cela a utilisé environ 8 minutes et environ 1,5 Go de mémoire.

Comment ça fonctionne

Nous partons du principe (sans aucune justification particulière) que A et B sont la gamme évidente d'entiers consécutifs centrée à 0 ou ½, puis faire une recherche A * pour une optimale C donnée A et B .

Axiom, score 1466

)time on

g(a:List INT,b:List INT,c:List INT):List INT==
   s:List INT:=[]
   for i in 1..#a repeat
     for j in 1..#b repeat
       for h in 1..#c repeat
            s:=cons(a.i*b.j+c.h, s)
   removeDuplicates(s)

inc(a:List INT, b:INT):List INT==
    #a=0=>a
    i:=1; len:=#a
    repeat
       if i>len then
             for j in 1..len repeat a.j:=0
             return a
       if i<len then 
         if a.i<a.(i+1) then
               if a.i<b then  
                          a.i:=a.i+1
                          for j in 1..(i-1) repeat a.j:=0
                          break
               for j in 1..i repeat a.j:=0 
       else 
         if a.i<b then 
                   a.i:=a.i+1
                   for j in 1..(len-1) repeat a.j:=0
                   break
       i:=i+1
    a

f(n:PI):List List INT==
   a:List INT:=[0];  b:List INT:=[0];   c :List INT:=[0]
   aix:List INT:=[]; cmin:List INT:=[]; cp:List INT:=[ ]
   s:List INT :=[ ];   c1:List INT:=[0]; smin:INT
   -- costruisce gli insiemi a,b
   i:=1
   for j in 1..n-1 repeat 
      if member?(i,a) then (a:=cons(-i,a);b:=cons(-i,b);i:=i+1)
      else                 (a:=cons( i,a);b:=cons( i,b))
   if n=1 then return [a,b,c,[0],[1]]
   a:=sort(a)
   c :=copy(a); cmin:=copy(a); cp:=copy(a)
   for i in 1..n repeat c.i:=i-3
   for i in 1..n repeat aix:=cons(0, aix)
   -- ottimizzati per i vari casi... si parte da particolari insiemi c
   -- da cui fare le variazioni
   if n>=8         then c.n:=c.n+2  
   if n=10 or n=13 then c.(n-1):=c.(n-1)+2
   if n=9  or n=16 or n=19 then (c.(n-2):=c.(n-2)+1; c.(n-1):=c.(n-1)+1; c.n:=c.n+1)
   smin:=n*n+10  
   repeat
       for i in 1..n repeat cp.i:=c.i+aix.i
       k:=# g(a,b,cp)
       if k<smin then 
                smin:=k; 
                for i in 1..n repeat cmin.i:=cp.i 
                --output ["assign",c,aix,cmin, k]
       inc(aix, 3)
       --output aix
       i:=0;repeat(i:=i+1;if i>n or aix.i~=0 then break)
       if i>n then break
   [sort(a),sort(b),sort(cmin),g(a,b,cmin),[smin]]


h(n:PI):NNI==
    k:=0
    r:List List INT:=[]
    for i in 1..n repeat
         r:=f(i)
         output [i,r.5.1,r.1,r.3]
         k:=k+r.5.1
    k

Les ensembles seraient A = B = [- n / 2..n / 2] si n% 2 == 0 sinon A = B = [- n / 2 .. ((n / 2) +1)]

L'ensemble C est la somme du tableau sous la forme [-2, -1, .. (n-2)] pour un tableau arr [] de ce type [0,0,0,0,0] ou [0,1 , 1,1,2] ou [0,0,0,0,3] de sorte que le tableau auquel il appartient

 arr[i] <= arr[i+1] for i in 1..n-1

Si vous voulez être plus précis ou que votre PC est plus rapide, vous pouvez essayer d'augmenter `` 3 '' en `` inc (aix, 3) '', ce qui augmente le nombre de tableaux pour la variation de l'ensemble C et donc cela augmenterait la précision du résultat.

Dans les résultats, la chaîne imprimée est

 [n, |{a*b+c for a in A for b in B for c in C}|,A,C]

où B = A et | S | est le nombre d'élément de S

(6) -> h 20
   [1,1,[0],[0]]
   [2,3,[0,1],[- 2,- 1]]
   [3,5,[- 1,0,1],[- 2,- 1,0]]
   [4,10,[- 1,0,1,2],[- 2,- 1,0,1]]
   [5,13,[- 2,- 1,0,1,2],[- 2,- 1,0,1,2]]
   [6,21,[- 2,- 1,0,1,2,3],[- 2,- 1,0,1,2,3]]
   [7,25,[- 3,- 2,- 1,0,1,2,3],[- 2,- 1,0,1,2,3,4]]
   [8,35,[- 3,- 2,- 1,0,1,2,3,4],[- 2,- 1,1,2,3,5,6,9]]
   [9,39,[- 4,- 3,- 2,- 1,0,1,2,3,4],[- 2,1,2,4,5,6,8,9,12]]
   [10,53,[- 4,- 3,- 2,- 1,0,1,2,3,4,5],[- 2,- 1,2,3,4,6,7,8,11,12]]
   [11,59,[- 5,- 4,- 3,- 2,- 1,0,1,2,3,4,5],[- 2,- 1,0,2,3,4,5,7,8,9,12]]
   [12,76,[- 5,- 4,- 3,- 2,- 1,0,1,2,3,4,5,6],[- 2,- 1,0,3,4,5,6,8,9,10,11,14]]
   [13, 82, [- 6,- 5,- 4,- 3,- 2,- 1,0,1,2,3,4,5,6],[- 2,- 1,0,3,4,5,6,8,9,10,11,14,15]]
   [14, 103, [- 6,- 5,- 4,- 3,- 2,- 1,0,1,2,3,4,5,6,7],[- 2,- 1,0,3,4,5,6,7,9,10,11,12,13,16]]
   [15, 110, [- 7,- 6,- 5,- 4,- 3,- 2,- 1,0,1,2,3,4,5,6,7],[- 2,- 1,0,1,4,5,6,7,8,10,11,12,13,14,17]]
   [16, 134, [- 7,- 6,- 5,- 4,- 3,- 2,- 1,0,1,2,3,4,5,6,7,8],[- 2,- 1,0,1,4,5,6,7,8,9,11,12,13,15,16,19]]
   [17, 142, [- 8,- 7,- 6,- 5,- 4,- 3,- 2,- 1,0,1,2,3,4,5,6,7,8],[- 2,- 1,0,1,4,5,6,7,8,9,11,12,13,14,15,16,19]]
   [18, 169, [- 8,- 7,- 6,- 5,- 4,- 3,- 2,- 1,0,1,2,3,4,5,6,7,8,9],[- 2,- 1,0,1,2,3,4,6,7,8,9,10,11,12,15,16,17,20]]
   [19, 178, [- 9,- 8,- 7,- 6,- 5,- 4,- 3,- 2,- 1,0,1,2,3,4,5,6,7,8,9],[- 2,- 1,0,1,2,5,6,7,8,9,10,11,13,14,15,16,18,19,22]]
   [20, 208, [- 9,- 8,- 7,- 6,- 5,- 4,- 3,- 2,- 1,0,1,2,3,4,5,6,7,8,9,10],[- 2,- 1,0,1,2,3,4,5,7,8,9,10,11,12,13,14,17,18,19,22]]

   (6)  1466
                                                    Type: PositiveInteger
      Time: 0.03 (IN) + 910.75 (EV) + 0.02 (OT) + 24.00 (GC) = 934.80 sec

SQL Server, 1495

declare @N int=20;
--set @N=40;
with
  n as(select 1 n union all select n+1 from n where n<@N),
  s as(select n,n/2-n+1 m from n union all select n,m+1 from s where m<n/2),
  t as(select n,m,row_number()over(partition by n order by m) p from s),
  a as(select n,m a,p from t),
  b as(select n,m b,p from t),
  c as(select n,m c,p from t),
  u as(
    select a.n,count(distinct a*b+c) q
    from a,b,c
    where b.n=a.n and c.n=a.n
    group by a.n
  )
select u.n,a,b,c,q,sum(distinct q) N
from u,a,b,c
where a.n=u.n and b.n=u.n and c.n=u.n and b.p=a.p and c.p=a.p
group by grouping sets((u.n,a,b,c,q),());

La solution peut être vérifiée ici .

Excusez-moi car la sortie est sous forme de tableau.

C, score 1448 1431

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define P printf
#define R return
#define F for

int cmp(const void*a,const void*b)
{int aa, bb;
 aa=*(int*)a; bb=*(int*)b;
 R aa>bb?1:(aa<bb?-1:0);
}

void show(int* a,unsigned n){unsigned i;P("[ ");F(i=0;i<n;++i) P("%d ", a[i]);P("]");}

// l'insieme "a" deve essere del tipo {0,1} {-1,0,1} {-1,0,1,2} {-2,-1,0,1,2} ecc di numero elementi n
// l'insieme "c" e' un insieme di numero elementi n
// l'insieme a cui "r" punta sarà *r={x*y+z : x in a, y in a, z in c }
// ritorna -1 per errore altrimenti il numero di elementi
// di {x*y+z : x in a, y in a, z in c }

int g(int**r,int*a,int*c,unsigned n)
{static int *arrs,*res;
 static unsigned  alen;
 unsigned i,j,k,m,v,vv,len;

 if(a==0||c==0||n<=0||n>128) R -1;
 len=n*n*n;
 if(alen<n)
    {if(arrs) free(arrs);  // leaks: arrs and res remain until the program end
     if(res ) free(res);
     arrs=0; res=0; alen=0;
     arrs=malloc(sizeof(int)*len);
     if(arrs==0)             R -1;
     res =malloc(sizeof(int)*len);
     if(res==0)
         {free(arrs); arrs=0;R -1;}
     alen=n;
    }
 v=0;
 F(k=0;k<n;++k) arrs[v++]=c[k]; // il caso 0 

 F(m=0;m<n&&a[m]<0;++m);// da una parte i positivi dall'altra i negativi; m punta a 0 
                        // il caso 0 non e' trattato
 F(i=0;i<m;++i)    // positivi per negativi
   F(j=m+1;j<n;++j)
      F(k=0;k<n;++k)
         if(-a[i]<=a[j]) arrs[v++]=a[i]*a[j]+c[k];
 F(i=m+1;i<n;++i)  // positivi per positivi
   F(j=i;j<n;++j)
      F(k=0;k<n;++k)
          arrs[v++]=a[i]*a[j]+c[k];
 qsort(arrs,v,sizeof(int),cmp);
 res[0]=arrs[0];  // elimina i doppioni
 F(vv=1,i=1; i<v; ++i)
       if(arrs[i-1]!=arrs[i]) res[vv++]=arrs[i];
 *r=res;
 R vv;
}


int inc(int* a,int len,int b)
{int i,j;
 if(len<1||b<1)R 1;
 F(i=0;;)
   {if(i>=len)
         {F(j=0;j<len;++j)a[j]=0;
          R 1;
         }
    if(i==len-1||a[i]<a[i+1])
               {if(a[i]<b)
                   {a[i]+=1;
                    F(j=0;j<i;++j)a[j]=0;
                    break;
                   }
               }
    i+=1;
   }
 R 0;
}

// a,b,c,cmin sono array e devono avere size n
// s          e' un array deve avere size n*n*n
//            come risultato la sua lunghezza e' *slen
//
int f(int* a,int* b,int* cmin,int* s,int* slen, int n)
{int i,j,k, *c, *aix, *cp, smin, *rs;

 if(slen)*slen=0;
 if(n<1||a==0||b==0||cmin==0||s==0||slen==0)R -1;

 // costruisce a e b
 j=-n/2;
 if(n%2==0)++j;
 F(i=0;i<n;++i,++j) s[i]=cmin[i]=a[i]=b[i]=j;
 // {-x..x}  oppure {-x..(x+1)}

 *slen=n;
 if(n==1)R 1; // caso di un solo elemento
 c  =malloc(sizeof(int)*(n+1)); // **
 if(c==0)R -1;
 aix=malloc(sizeof(int)*(n+1)); // **
 if(aix==0){free(c);R -1;}
 cp =malloc(sizeof(int)*(n+1)); // **
 if(cp==0){free(aix);free(c);R -1;}

 F(i=0;i<n;++i){cp[i]=aix[i]=0;c[i]=i;}
 if(n>=16)//16
    {c[n-1]=c[n-1]+3;c[n-2]=c[n-2]+3;c[n-3]=c[n-3]+3;}
 F(smin=n*n+10;;)
    {cp[0]=c[0];
     F(i=1;i<n;++i) cp[i]=c[i]+aix[i-1];
     k=g(&rs,a,cp,n);
     if(k<smin){F(smin=k,i=0;i<n;++i) cmin[i]=cp[i];
                //P("Assign: %d,  ", k);
                //show(aix,n);P(",");
                //P("Cmin=");show(cmin,n);P("\n");
               }
     //show(aix,n);P("\n");
     if(inc(aix,n-1,7))break;
    }
 free(cp);free(aix);free(c);
 k=g(&rs,a,cmin,n);
 if(k==-1)R -1;
 F(i=0;i<k;++i)s[i]=rs[i];
 *slen=k;
 R k;
}

unsigned h(unsigned nmax)
{time_t                             ti, tf;
 double  dft;
 int i,j, *a, *b, *cmin, *s, slen, rlen, r;
 unsigned                            n,len;
 if(nmax>128||nmax<1)R -1;
 len =nmax*nmax*nmax+1;
 s   =malloc(sizeof(int)*len);      // **
 a   =malloc(sizeof(int)*(nmax+1)); // **
 b   =malloc(sizeof(int)*(nmax+1)); // **
 cmin=malloc(sizeof(int)*(nmax+1)); // **
 if(s==0||a==0||b==0||cmin==0){free(s);free(a);free(b);free(cmin);R -1;}
 ti=time(0);
 F(n=1,r=0;n<=nmax;++n)
    {rlen=f(a,b,cmin,s,&slen,n);
     if(rlen!=-1)
         {P("%d %d", n, rlen); show(cmin,n);P("\n");}
     else break;
     r+=rlen;
    }
 tf=time(0);
 dft=difftime(tf, ti);
 P("Result=%d  secondi=%.0f  minuti=%.0f\n", r, dft, dft/60.0);
free(s);free(a);free(b);free(cmin);
 R r;
}

int main(){h(20); R 0;}

Ce serait le même +/- algo de la mise en œuvre d'Axiom

résultats

1 1[ 0 ]
2 3[ 0 1 ]
3 5[ 0 1 2 ]
4 10[ 0 1 2 3 ]
5 13[ 0 1 2 3 4 ]
6 21[ 0 1 2 3 4 5 ]
7 25[ 0 1 2 3 4 5 6 ]
8 35[ 0 1 3 4 5 7 8 11 ]
9 39[ 0 3 4 6 7 8 10 11 14 ]
10 53[ 0 1 4 5 6 8 9 10 13 14 ]
11 59[ 0 1 2 4 5 6 7 9 10 11 14 ]
12 75[ 0 1 2 5 6 7 8 11 12 13 17 18 ]
13 81[ 0 1 2 5 6 7 8 11 12 13 14 17 18 ]
14 101[ 0 1 2 3 6 7 8 9 10 13 14 15 16 20 ]
15 107[ 0 1 2 3 6 7 8 9 10 13 14 15 16 20 21 ]
16 130[ 0 1 2 6 7 8 9 10 13 14 15 16 17 21 22 23 ]
17 137[ 0 1 2 3 7 8 9 10 11 15 16 17 18 19 23 24 25 ]
18 163[ 0 1 2 3 7 8 9 10 11 12 16 17 18 19 20 25 26 27 ]
19 171[ 0 1 2 3 4 8 9 10 11 12 13 17 18 19 20 21 26 27 28 ]
20 202[ 0 1 2 3 7 8 9 10 11 12 13 17 18 19 20 21 22 27 28 29 ]
Result=1431  secondi=618  minuti=10

Python 2 , score 1495

f=lambda n:range(-n/2+1,n/2+1)
f_A=f_B=f_C=f

def comb_set(A, B, C):
	return sorted({a*b+c for a in A for b in B for c in C})

def S(n):
	return comb_set(f_A(n), f_B(n), f_C(n))

Essayez-le en ligne!

Une ligne de base simple pour que chaque ensemble soit un intervalle de longueur n centré autour de 0, légèrement déséquilibré même pour n. Le TIO a du code Python pour calculer votre score.

1   1
2   3
3   5
4   10
5   13
6   21
7   25
8   36
9   41
10  55
11  61
12  78
13  85
14  105
15  113
16  136
17  145
18  171
19  181
20  210

Total: 1495

La taille est (n*n+1)/2pour n impair et (n*n+n)/2pour n pair.

Mathematica, score 1495

z = 0;
For[n = 1, n <= 20, n++,
r = Range[n] - Ceiling[n/2];
Print["S_n size=", x = (s = Length@#;
  Length@
   Union@Flatten@
     Table[#[[i]]*#[[j]] + #[[k]], {i, s}, {j, s}, {k, s}]) &[r], 
"  ", "A=B=C=", r]; z = z + x]
Print["SCORE=", z]

Taille S_n = 1 A = B = C = {0}
Taille S_n = 3 A = B = C = {0,1}
Taille S_n = 5 A = B = C = {- 1,0,1}
Taille S_n = 10 A = B = C = {- 1,0,1,2}
taille S_n = 13 A = B = C = {- 2, -1,0,1,2}
taille S_n = 21 A = B = C = { -2, -1,0,1,2,3}
taille S_n = 25 A = B = C = {- 3, -2, -1,0,1,2,3}
taille S_n = 36 A = B = C = {- 3, -2, -1,0,1,2,3,4}
S_n taille = 41 A = B = C = {- 4, -3, -2, -1,0,1,2 , 3,4}
taille S_n = 55 A = B = C = {- 4, -3, -2, -1,0,1,2,3,4,5}
taille S_n = 61 A = B = C = {-5, -4, -3, -2, -1,0,1,2,3,4,5}
taille S_n = 78 A = B = C = {- 5, -4, -3, -2 , -1,0,1,2,3,4,5,6}
S_n taille = 85 A = B = C = {- 6, -5, -4, -3, -2, -1,0,1 , 2,3,4,5,6}
S_n taille = 105 A = B = C = {- 6, -5, -4, -3, -2, -1,0,1,2,3,4, 5,6,7}
S_n taille = 113 A = B = C = {- 7, -6, -5, -4, -3, -2, -1,0,1,2,3,4,5, 6,7}
S_n taille = 136 A = B = C = {- 7, -6, -5, -4, -3, -2, -1,0,1,2,3,4,5,6,7,8}
Taille S_n = 145 A = B = C = {- 8, -7, -6, -5, -4, -3, -2, -1,0,1,2,3,4,5,6,7 , 8}
S_n taille = 171 A = B = C = {- 8, -7, -6, -5, -4, -3, -2, -1,0,1,2,3,4,5, 6,7,8,9}
S_n taille = 181 A = B = C = {- 9, -8, -7, -6, -5, -4, -3, -2, -1,0,1, 2,3,4,5,6,7,8,9}
S_n taille = 210 A = B = C = {- 9, -8, -7, -6, -5, -4, -3, -2 , -1,0,1,2,3,4,5,6,7,8,9,10}
SCORE = 1495

C ++, score 1411

Les conjectures A et B sont des entiers consécutifs centrés près de 0, utilisez simplement le recuit simulé pour trouver C.

La source:

#include <algorithm>
#include <iostream>
#include <random>
#include <bitset>
#include <cmath>

using namespace std;

using bools = bitset<270>;
using irand = uniform_int_distribution<int>;
ranlux48 gen;
uniform_real_distribution<double> frand(0, 1);

int evaluate(const bools& a, const vector<int>& v)
{
    bools t = a;
    for (int i : v) t |= a << i;
    return t.count();
}

vector<int> best;
int best_score, prev_score;

void transition(double Temp, int Q, const bools& a, vector<int>& now)
{
    int rep, pos, tmp;
    do rep = irand(1, Q)(gen); while (find(now.begin(), now.end(), rep) != now.end());
    pos = irand(0, now.size() - 1)(gen);
    tmp = now[pos];
    now[pos] = rep;
    int now_score = evaluate(a, now);
    if (now_score <= prev_score || frand(gen) < exp((double)(prev_score - now_score))) {
        prev_score = now_score;
        if (now_score < best_score) best_score = now_score, best = now;
    }
    else now[pos] = tmp;
}

int main()
{
    int score = 0;
    for (int N = 1; N <= 20; N++) {
        gen.seed(0);
        int first = -N / 2, last = first + N, Q = N * 3;
        bools st;

        for (int i = first; i < last; i++)
            for (int j = first; j < last; j++)
                st[i * j + last * last] = true;

        vector<int> lst;
        for (int i = 1; i < N; i++) lst.push_back(i);

        best = lst;
        prev_score = best_score = evaluate(st, lst);

        if (N != 1)
            for (double Temp = 70.; Temp > 0; Temp -= 3e-5) transition(Temp, Q, st, lst);
        sort(best.begin(), best.end());
        cout << "N = " << N << "; |S| = " << best_score << endl;
        cout << " A = B = {";
        for (int i = first; i < last; i++) cout << i << (i != last - 1 ? ", " : "}\n");
        cout << " S = {0";
        for (int i : best) cout << ", " << i;
        cout << "}\n";

        score += best_score;
    }
    cout << "Score: " << score << endl;
}

Résultats:

N = 1; |S| = 1
 A = B = {0}
 S = {0}
N = 2; |S| = 3
 A = B = {-1, 0}
 S = {0, 1}
N = 3; |S| = 5
 A = B = {-1, 0, 1}
 S = {0, 1, 2}
N = 4; |S| = 10
 A = B = {-2, -1, 0, 1}
 S = {0, 1, 2, 3}
N = 5; |S| = 13
 A = B = {-2, -1, 0, 1, 2}
 S = {0, 1, 2, 3, 4}
N = 6; |S| = 21
 A = B = {-3, -2, -1, 0, 1, 2}
 S = {0, 1, 2, 3, 4, 5}
N = 7; |S| = 25
 A = B = {-3, -2, -1, 0, 1, 2, 3}
 S = {0, 1, 2, 3, 4, 5, 6}
N = 8; |S| = 35
 A = B = {-4, -3, -2, -1, 0, 1, 2, 3}
 S = {0, 3, 4, 6, 7, 10, 11, 14}
N = 9; |S| = 39
 A = B = {-4, -3, -2, -1, 0, 1, 2, 3, 4}
 S = {0, 3, 4, 6, 7, 8, 10, 11, 14}
N = 10; |S| = 53
 A = B = {-5, -4, -3, -2, -1, 0, 1, 2, 3, 4}
 S = {0, 1, 4, 5, 6, 9, 10, 11, 14, 15}
N = 11; |S| = 58
 A = B = {-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5}
 S = {0, 1, 4, 5, 6, 9, 10, 11, 14, 15, 19}
N = 12; |S| = 74
 A = B = {-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5}
 S = {0, 4, 5, 6, 9, 10, 11, 12, 15, 16, 17, 21}
N = 13; |S| = 80
 A = B = {-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6}
 S = {0, 6, 10, 11, 12, 15, 16, 17, 18, 21, 22, 23, 27}
N = 14; |S| = 100
 A = B = {-7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6}
 S = {0, 5, 6, 7, 11, 12, 13, 14, 18, 19, 20, 21, 25, 26}
N = 15; |S| = 106
 A = B = {-7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7}
 S = {0, 5, 6, 7, 11, 12, 13, 14, 18, 19, 20, 21, 25, 26, 32}
N = 16; |S| = 128
 A = B = {-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7}
 S = {0, 6, 7, 8, 13, 14, 15, 16, 21, 22, 23, 24, 29, 30, 31, 37}
N = 17; |S| = 135
 A = B = {-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8}
 S = {0, 6, 7, 8, 13, 14, 15, 16, 21, 22, 23, 24, 29, 30, 31, 37, 45}
N = 18; |S| = 161
 A = B = {-9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8}
 S = {0, 7, 8, 9, 14, 15, 16, 17, 18, 22, 23, 24, 25, 26, 31, 32, 33, 40}
N = 19; |S| = 167
 A = B = {-9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
 S = {0, 7, 8, 9, 15, 16, 17, 18, 23, 24, 25, 26, 27, 32, 33, 34, 35, 41, 42}
N = 20; |S| = 197
 A = B = {-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
 S = {0, 8, 9, 10, 16, 17, 18, 19, 20, 25, 26, 27, 28, 29, 35, 36, 37, 38, 45, 46}
Score: 1411

Avec -O2 sur mon ordinateur, il faut 50 secondes pour calculer tous les résultats.