CF580D Kefa and Dishes

CF580D Kefa and Dishes

题解

这题是用来智力康复的。。。
设$f[S][i]$为当前已选菜的状态为S，最后一个菜为i的最大满意度
然后转移即可

code:

#include<bits/stdc++.h>
#define int long long
using namespace std;
int n, m, k, a[25], val[25][25], f[(1<<18)+5][25];
signed main(){
	scanf("%lld%lld%lld", &n, &m, &k);
	for(int i = 1; i <= n; i ++) scanf("%lld", &a[i]), f[1ll << (i - 1)][i] = a[i];
	for(int i = 1; i <= k; i ++){
		int x, y, z;
		scanf("%lld%lld%lld", &x, &y, &z);
		val[x][y] = z; 
	}
	for(int S = 0; S < (1 << n); S ++){
		for(int i = 1; i <= n; i ++) if((1 << (i - 1)) & S) {
			for(int j = 1; j <= n; j ++) if(((1 << (j - 1)) & S) == 0){
				int S1 = S | (1 << (j - 1));
				f[S1][j] = max(f[S1][j], f[S][i] + a[j] + val[i][j]);
			}
		}
	}
	int ans = 0;
	for(int S = 0; S < (1 << n); S ++){
		int ret = 0;
		for(int i = 1; i <= n; i ++) if(S & (1 << (i - 1))) ret ++;
		
		if(ret == m){
			for(int i = 1; i <= n; i ++)
				ans = max(ans, f[S][i]);
		}
	}
	printf("%lld", ans);
	return 0;
}

智力仍需康复