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

Code mẫu của happyboy99x

#include<cstdio>
#include<climits>

const int N = 20;
int f[1 << N], a[N][N], n;
long long c[1 << N];

void enter() {
    scanf("%d", &n);
    for(int i = 0; i < n; ++i)
        for(int j = 0; j < n; ++j)
            scanf("%d", &a[i][j]);
}

int snoob(const int &x) {
    int r = x & -x, h = x + r;
    return h | (x ^ h) / r >> 2;
}

void solve() {
    const int Omega = 1 << n;
    f[0] = 0; c[0] = 1;
    for(int i = 0; i < n; ++i)
        for(int s = (1 << (i+1)) - 1; s < Omega; s = snoob(s)) {
            f[s] = INT_MIN;
            for(int p = 0; p < n; ++p) if(s & 1 << p) {
                const int ss = s & ~(1 << p);
                if(f[ss] + a[i][p] > f[s]) {
                    f[s] = f[ss] + a[i][p];
                    c[s] = c[ss];
                } else if(f[ss] + a[i][p] == f[s])
                    c[s] += c[ss];
            }
        }
    printf("%d %lld\n", f[Omega - 1], c[Omega - 1]);
}

int main() {
    enter();
    solve();
    return 0;
}

Code mẫu của ladpro98

program maugiao;
uses    math;
const   maxn=20;
        maxV=1 shl maxn;
        fi='';
var     a:array[0..maxn,0..maxn] of longint;
        f:array[-1..maxV] of longint;
        way:array[0..maxV] of int64;
        n,m:longint;

procedure input;
var     inp:text;
        i,j:longint;
begin
        assign(inp,fi);
        reset(inp);
        readln(inp,n);
        for i:=1 to n do
        begin
                for j:=1 to n do read(inp,a[i,j]);
                readln(inp);
        end;
        close(inp);
end;

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

procedure dp;
var     i,j,t,p:longint;
begin
        way[0]:=1;
        for j:=1 to 1 shl n - 1 do
        begin
                t:=0;
                for i:=1 to n do
                if getbit(j,i) then inc(t);
                for i:=1 to n do
                if getbit(j,i) then
                begin
                        p:=f[j-1 shl (i-1)]+a[t,i];
                        if f[j]<p then
                        begin
                                f[j]:=p;
                                way[j]:=way[j-1 shl (i-1)];
                        end
                        else
                        if f[j]=p then way[j]:=way[j]+way[j-1 shl (i-1)];
                end;
        end;
end;

begin
        input;
        dp;
        write(f[1 shl n-1],' ',way[1 shl n -1]);
end.

Code mẫu của RR

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <iomanip>
#include <bitset>
#include <complex>

#define FOR(i,a,b) for(i = a; i <= b; ++i)
#define REP(i,a) for(i = 0; i < a; ++i)
#define MP make_pair
#define PB push_back
#define F first
#define S second
using namespace std;

#define TWO(x) (1<<(x))
#define CONTAIN(S,x) (S & TWO(x))
;

int f[1100111], n, a[22][22];
long long g[1100111];
vector<int> ls[22];

int main() {
    int i, mask, j;
    scanf("%d", &n); FOR(i,1,n) FOR(j,1,n) scanf("%d", &a[i][j]);
    f[0] = 0;
    g[0] = 1;

    int cnt;
    REP(mask,TWO(n)) {
        cnt = 0;
        REP(i,n)
            if (CONTAIN(mask,i)) ++cnt;
        ls[cnt].PB(mask);
    }

    int cur, mask2, x, sz;
    FOR(i,0,n-1) {
        sz = ls[i].size();
        REP(x,sz) {
            mask = ls[i][x];
            if (!*(g+mask)) continue;
            REP(j,n) if (!CONTAIN(mask,j)) {
                cur = *(f+mask) + a[i+1][j+1];
                mask2 = mask + TWO(j);
                if (cur > *(f+mask2)) {
                    *(f+mask2) = cur;
                    *(g+mask2) = *(g+mask);
                }
                else if (cur == *(f+mask2))
                    *(g+mask2) += *(g+mask);
            }
        }
    }
    cout << f[TWO(n)-1] << ' ' << g[TWO(n)-1] << endl;
    return 0;
}

Code mẫu của hieult

#include <set>
#include <map>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <sstream>
#include <iomanip>
#include <iostream>
#include <algorithm>
#include <ctime>
#include <deque>
#include <bitset>
#include <cctype>
#include <utility>

using namespace std;

typedef long long ll;
typedef double ld;
typedef unsigned int ui;
typedef unsigned long long ull;

#define Rep(i,n) for(int i = 0; i < (n); ++i)
#define Repd(i,n) for(int i = (n)-1; i >= 0; --i)
#define For(i,a,b) for(int i = (a); i <= (b); ++i)
#define Ford(i,a,b) for(int i = (a); i >= (b); --i)
#define Fit(i,v) for(__typeof((v).begin()) i = (v).begin(); i != (v).end(); ++i)
#define Fitd(i,v) for(__typeof((v).rbegin()) i = (v).rbegin(); i != (v).rend(); ++i)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define sz(a) ((int)(a).size())
#define all(a) (a).begin(), (a).end()
#define ms(a,x) memset(a, x, sizeof(a))

template<class F, class T> T convert(F a, int p = -1) {
    stringstream ss;
    if (p >= 0)
        ss << fixed << setprecision(p);
    ss << a;
    T r;
    ss >> r;
    return r;
}
template<class T> T gcd(T a, T b) {
    T r;
    while (b != 0) {
        r = a % b;
        a = b;
        b = r;
    }
    return a;
}
template<class T> T lcm(T a, T b) {
    return a / gcd(a, b) * b;
}
template<class T> T sqr(T x) {
    return x * x;
}
template<class T> T cube(T x) {
    return x * x * x;
}
template<class T> int getbit(T s, int i) {
    return (s >> i) & 1;
}
template<class T> T onbit(T s, int i) {
    return s | (T(1) << i);
}
template<class T> T offbit(T s, int i) {
    return s & (~(T(1) << i));
}
template<class T> int cntbit(T s) {
    return s == 0 ? 0 : cntbit(s >> 1) + (s & 1);
}

const int bfsz = 1 << 16;
char bf[bfsz + 5];
int rsz = 0;
int ptr = 0;
char gc() {
    if (rsz <= 0) {
        ptr = 0;
        rsz = (int) fread(bf, 1, bfsz, stdin);
        if (rsz <= 0)
            return EOF;
    }
    --rsz;
    return bf[ptr++];
}
void ga(char &c) {
    c = EOF;
    while (!isalpha(c))
        c = gc();
}
int gs(char s[]) {
    int l = 0;
    char c = gc();
    while (isspace(c))
        c = gc();
    while (c != EOF && !isspace(c)) {
        s[l++] = c;
        c = gc();
    }
    s[l] = '\0';
    return l;
}
template<class T> bool gi(T &v) {
    v = 0;
    char c = gc();
    while (c != EOF && c != '-' && !isdigit(c))
        c = gc();
    if (c == EOF)
        return false;
    bool neg = c == '-';
    if (neg)
        c = gc();
    while (isdigit(c)) {
        v = v * 10 + c - '0';
        c = gc();
    }
    if (neg)
        v = -v;
    return true;
}

typedef pair<int, unsigned long long> II;
const ld PI = acos(-1.0);
const ld eps = 1e-9;
const int dr[] = { 0, 0, -1, +1 , -1, -1, +1, +1};
const int dc[] = { -1, +1, 0, 0 , -1, +1, -1, +1};
const int inf = (int) 1e9 + 5;
const ll linf = (ll) 1e16 + 5;
const ll mod = (ll) 1e9 + 7;

#define maxn 20

int n, a[maxn][maxn], u;
II f[(1 << maxn)];

II comp(II P0, II P1){
    if(P0.fi == P1.fi) return mp(P0.fi, P0.se + P1.se);
    if(P0.fi < P1.fi) return P1;
    else return P0;
}

int main() {
//  freopen("in.txt", "r", stdin);

    cin >> n;
    Rep(i, n) Rep(j, n) cin >> a[i][j];
    f[0] = mp(0, 1);
    For(mask, 1, (1 << n) - 1){
        u = cntbit(mask) - 1;
        Rep(i, n) if(getbit(mask, i)){
            f[mask] = comp(f[mask], mp(f[offbit(mask, i)].fi + a[u][i], f[offbit(mask, i)].se));
        }
    }
//  cout << f[1].fi << " " << f[1].se << endl;
    cout << f[(1 << n) - 1].fi << " " << f[(1 << n) - 1].se << endl;
//  cout << clock() << endl;

    return 0;
}