CF580D Kefa and Dishes （状压DP）

枚举最后食物

#include <iostream>

#include <cstdio>

#include <cstring>

#include <algorithm>

#include <cmath>

#define R(a,b,c) for(register int  a = (b); a <= (c); ++ a)

#define nR(a,b,c) for(register int  a = (b); a >= (c); -- a)

#define Max(a,b) ((a) > (b) ? (a) : (b))

#define Min(a,b) ((a) < (b) ? (a) : (b))

#define Fill(a,b) memset(a, b, sizeof(a))

#define Abs(a) ((a) < 0 ? -(a) : (a))

#define Swap(a,b) a^=b^=a^=b

#define ll long long

#define ON_DEBUG

#ifdef ON_DEBUG

#define D_e_Line printf("\n\n----------\n\n")

#define D_e(x)  cout << #x << " = " << x << endl

#define Pause() system("pause")

#define FileOpen() freopen("in.txt","r",stdin);

#else

#define D_e_Line ;

#define D_e(x)  ;

#define Pause() ;

#define FileOpen() ;

#endif

struct ios{

    template<typename ATP>ios& operator >> (ATP &x){

        x = 0; int f = 1; char c;

        for(c = getchar(); c < '0' || c > '9'; c = getchar()) if(c == '-')  f = -1;

        while(c >= '0' && c <= '9') x = x * 10 + (c ^ '0'), c = getchar();

        x*= f;

        return *this;

    }

}io;

using namespace std;

#define int long long

int a[19], val[19][19], f[(1 << 18) + 7][19];

#undef int

int main(){

#define int long long

	int n, m, k;

    io >> n >> m >> k;

    R(i,1,n)

        io >> a[i];

    R(i,1,k){

    	int x, y;

    	io >> x >> y;

    	io >> val[x][y];

    }

    R(i,1,n)

        f[1 << (i - 1)][i]=a[i];

	int ans = 0;

    R(s,0,(1 << n) - 1){

        int tot=0;

        R(i,1,n)

			if(s & (1 << (i - 1))){

	            ++tot;

	            R(j,1,n)

					if(!(s & (1 << (j - 1)))){

						f[s | (1 << (j - 1))][j] = Max(f[s | (1 << (j - 1))][j] , f[s][i] + a[j] + val[i][j]);

					}

	        }

	        if(tot == m)

	        	R(i,1,n)

					if(s & (1 << (i - 1)))

	            		ans = Max(ans , f[s][i]);

    }

    printf("%lld", ans);

    return 0;

}

CF580D Kefa and Dishes （状压DP）的相关教程结束。