Lưu ý: Các code mẫu dưới đây chỉ mang tính tham khảo và có thể không AC được bài tập này

Code mẫu của flashmt

const fi='';
      fo='';
      maxn=15;
var n,i:longint;
    p:array[0..maxn] of longint;
    d:array[0..1 shl maxn] of boolean;
    a:array[1..1 shl maxn+10] of word;

procedure att(i:longint);
var j,x,k,q:longint;
begin
     for j:=0 to n-1 do
     begin
          x:=a[i-1] xor p[j];
          if (i=p[n]+1) and (x=0) then
          begin
               a[i]:=0;
               for k:=1 to i do
               begin
                    for q:=0 to n-1 do
                         if a[k] shr q and 1=1 then write('X') else write('O');
                    writeln;
               end;
               close(output); halt;
          end;
          if not d[x] then
          begin
               a[i]:=x;
               d[x]:=true;
               att(i+1);
               d[x]:=false;
          end;
     end;
end;

begin
     assign(input,fi); reset(input);
     assign(output,fo); rewrite(output);
     read(n);
     close(input);
     for i:=0 to maxn do p[i]:=1 shl i;
     d[0]:=true; a[1]:=0;
     att(2);
end.

Code mẫu của happyboy99x

#include <algorithm>
#include <bitset>
#include <cctype>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;

typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<vii> vvii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef long long LL;

#define sz(a) (int((a).size()))
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define all(c) (c).begin(), (c).end()
#define tr(c,i) for(typeof((c).begin()) i = (c).begin(), _e = (c).end(); i != _e; ++i)
#define present(c,x) ((c).find(x) != (c).end())
#define cpresent(c,x) (find(all(c),x) != (c).end())
#define rep(i,n) for(int i = 0, _n = (n); i < _n; ++i)
#define repd(i,n) for(int i = (n)-1; i >= 0; --i )
#define fo(i,a,b) for(int i = (a), _b = (b); i <= _b; ++i)
#define fod(i,a,b) for(int i = (a), _b = (b); i >= _b; --i)

#define INF 1000000000
#define N

int f[(1<<15)+1];

int main() {
    int n; scanf("%d",&n);
    rep(k,n) for(int i=0, j = (1<<k+1)-1; i < j; ++i, --j)
        f[j] = f[i] | (1 << k);
    rep(i,(1<<n)+1) {
        repd(j,n) putchar(f[i]&(1<<j) ? 'X' : 'O');
        putchar(10);
    }
    return 0;
}

Code mẫu của ladpro98

program rocks;
uses    math;
const   maxN=15;
        maxV=1 shl maxN;
        fi='';
var     f:array[1..maxN,0..maxV] of longint;
        n:longint;

procedure input;
var     f:text;
begin
        assign(f,fi);
        reset(f);
        readln(f,n);
        close(f);
end;

function getbit(n,i:longint):longint;
begin
        exit((n shr (i-1)) and 1);
end;

procedure graycode;
var     i,j:longint;
begin
        f[1,1]:=0;
        f[1,2]:=1;
        for i:=2 to n do
        for j:=1 to 1 shl i do
        begin
                if j<=(1 shl (i-1)) then
                f[i,j]:=f[i-1,j]
                else
                f[i,j]:=f[i-1,(1 shl i)-j+1]+(1 shl (i-1));
        end;
end;

procedure output;
var     i,j:longint;
begin
        for i:=1 to 1 shl n do
        begin
                for j:=1 to n do
                if getbit(f[n,i],j)=1 then write('X')
                else write('O');
                writeln;
        end;
        for i:=1 to n do
        write('O');
end;

begin
        input;
        graycode;
        output;
end.

Code mẫu của RR

#include <iostream>
#include <algorithm>
#define FOR(i,a,b) for(long i=a; i<=b; i++)
using namespace std;

long a[20],n;

void solve(long i) {
    if (i==n+1) {
        FOR(i,1,n)
            if (a[i]) printf("X");
            else printf("O");
        printf("\n");
        return ;
    }
    solve(i+1);
    a[i]=1-a[i];
    solve(i+1);
}

int main() {
//    freopen("input.txt","r",stdin);
//    freopen("output.txt","w",stdout);
    scanf("%ld",&n);
    solve(1);
    FOR(i,1,n) printf("O");
    printf("\n");
    return 0;
}

Code mẫu của hieult

#include <stdio.h>
//#include <conio.h>

main()

{
      int s[35000][17],C[17],n;
      scanf("%d",&n);
      C[0]=1;
      for(int i=1;i<=n;i++)
          C[i]=C[i-1]*2;
      for(int i=1;i<=n;i++)
      {
          for(int j=1;j<=C[i-1];j++)
              s[j][i]=0;
          for(int j=C[i-1]+1;j<=C[i];j++)
          {
              for(int k=1;k<=i-1;k++)
                  s[j][k]=s[C[i]+1-j][k];
              s[j][i]=1;
          }
      }
      for(int i=1;i<=C[n];i++)
      {
          for(int j=1;j<=n;j++)
          {
              if(s[i][j]==0)
                  printf("O");
              else printf("X");
          }
          printf("\n");
      }
      for(int i=1;i<=n;i++)
          printf("O");
      //getch();
}

Code mẫu của ll931110

{
ID: ll9311102
PROB: rocks
LANG: PASCAL
}

program rocks;
const
  input  = '';
  output = '';
  maxn = 16;
  maxk = 100000;
type
  pnode = ^tnode;
  tnode = record
    val: longint;
    link: pnode;
  end;
var
  a: array[0..maxk] of pnode;
  fin,list: array[0..maxk] of longint;
  free: array[0..maxk] of boolean;
  flag: boolean;
  n: longint;
  fi,fo: text;

procedure openfile;
begin
  assign(fi, input);  reset(fi);
  assign(fo, output);  rewrite(fo);
end;

procedure closefile;
begin
  close(fo);  close(fi);
end;

procedure add(x,y: longint);
var
  p: pnode;
begin
  new(p);
  p^.val := y;
  p^.link := a[x];
  a[x] := p;
end;

procedure load;
var
  i,j,v: longint;
begin
  readln(fi, n);
  for i := 0 to 1 shl n do a[i] := nil;
  for i := 0 to 1 shl n - 1 do
      for j := 0 to n - 1 do
        begin
          if i and (1 shl j) = 0 then v := i + (1 shl j) else v := i - (1 shl j);
          add(i,v);
        end;
end;

procedure Ham(i: longint);
var
  p: pnode;
  u,v: longint;
begin
  if flag then exit;
  u := list[i - 1];
  free[u] := false;
  p := a[u];

  while p <> nil do
    begin
      v := p^.val;
      if (v = 0) and (i = 1 shl n) then
        begin
          flag := true;
          fin := list;
          exit;
        end;

      if free[v] then
        begin
          list[i] := v;
          if i < 1 shl n then Ham(i + 1);
        end;

      p := p^.link;
    end;
end;

procedure solve;
begin
  flag := false;
  fillchar(free, sizeof(free), true);
  Ham(1);
end;

procedure printresult;
var
  i,j: longint;
  u: longint;
begin
  for i := 0 to 1 shl n do
    begin
      u := list[i];
      for j := n - 1 downto 0 do
        if u and (1 shl j) = 0 then write(fo, 'O') else write(fo, 'X');
      writeln(fo);
    end;
end;

begin
  openfile;
  load;
  solve;
  printresult;
  closefile;
end.

Code mẫu của khuc_tuan

#include <string>
#include <iostream>
#include <vector>
using namespace std;

vector<string> gen(int n) {
    vector<string> res;
    if(n == 1) {
        res.push_back("O"); res.push_back("X");
    }
    else {
        vector<string> tmp = gen(n - 1);
        for(int i=0;i<tmp.size();++i) res.push_back("O" + tmp[i]);
        for(int i=tmp.size()-1;i>=0;--i) res.push_back("X" + tmp[i]);   
    }
    return res;
}

int main() {
    int n;
    cin >> n;
    vector<string> res = gen(n);
    for(int i=0;i<res.size();++i) cout << res[i] << endl;
    cout << string(n,'O') << endl;
    return 0;   
}