2025“钉耙编程”中国大学生算法设计暑期联赛（1）——1003奸商 · znzryb

## 思路讲解

就是暴力枚举一下就行了。当然要预处理一下。

## AC代码

[https://acm.hdu.edu.cn/contest/view-code?cid=1172&rid=25007](https://acm.hdu.edu.cn/contest/view-code?cid=1172&rid=25007)



::: 源代码

```cpp
// Problem: 奸商
// Contest: HDOJ
// URL: https://acm.hdu.edu.cn/contest/problem?cid=1172&pid=1003
// Memory Limit: 262144 MB
// Time Limit: 1000 ms
// by Gospel_rock
// 
// Powered by CP Editor (https://cpeditor.org)

#include <bits/stdc++.h>
#define all(vec) vec.begin(),vec.end()
#define pb push_back
#define EB emplace_back
#define EM emplace
#define FI first
#define SE second
#define SZ(a) ((int) a.size())
#define FOR(i, a, b) for (long long i = (a); i <= (b); ++i)
#define ROF(i, a, b) for (long long i = (a); i >= (b); --i)
#define debug(var) cerr << #var <<":"<<var<<"\n";
#define lson(var) (var<<1)
#define rson(var) ((var<<1)+1)

using namespace std;

using  ll = long long;using ull = unsigned long long;
using DB=double;using LD=long double;
// using i128 = __int128;
using pdd = pair<DB,DB>;using plb = pair<ll,bool>;
using pll = pair<ll,ll>;using vll=vector<ll>;using vb=vector<bool>;
using tll = tuple<ll,ll,ll>;
using vpll = vector<pll>;
using arr3 = array<ll,3> ;using arr2 = array<ll,2>;
constexpr ll MAXN=(ll)3e3+10,INF=(ll)1e17+9; // 1e18+9也是素数
constexpr ll mod=(ll)1e9+7; // 998244353
constexpr double eps=1e-8;const double pi=acos(-1.0);
ll N,M,Q,X,K,T,lT,W[MAXN];
char S[MAXN];
/*

*/
inline void __(){
	cin>>N;
	FOR(i,1,N){
		cin>>S[i];
	}
	FOR(i,1,17){
		cin>>W[i];
	}
	ll len;cin>>len;
	if(N==1){
		cout<<0<<"\n";
		return;
	}
	vll bits;
	if(len%2==1){
		len+=1;
	}
	if(len>N){
		cout<<0<<"\n";
		return;
	}
	// 可以先O（n*n）预处理一下
	FOR(i,1,N){
		bitset<20> bi;
		bool ok=false;
		FOR(j,1,N){
			ll x=i-j+1,y=i+j;
			if(x<1 || y>N) break;
#ifdef LOCAL
    debug(x);debug(y);
#endif
			if(S[x]!=S[y]){
				bi[min(S[x],S[y])-'a']=true;
			}else{
				ok=true;
			}
			if(y-x+1==len){
				if(ok) continue;
				 bits.pb(bi.to_ullong());
			}
		}
	}
	sort(all(bits));bits.resize(unique(all(bits))-bits.begin());
	ll ans=INF;
#ifdef LOCAL
    for(auto &b:bits){
    	bitset<20> bi(b);
    	FOR(i,0,17){
    		cerr<<bi[i];
    	}
    	cerr<<"\n";
    }
    FOR(i,0,17){
   		cerr<<char('a'+i);
   	}
   	cerr<<"\n";
    FOR(i,1,17){
   		cerr<<W[i];
   	}
   	cerr<<"\n";
#endif
	FOR(s,0,(1<<17)-1){
		bitset<20> bi(s);
		ll lans=0;
		FOR(j,0,18){
			if(bi[j]){
				lans+=W[j+1];
			}
		}
		if(lans>=ans) continue;
		bool ok=true;
		for(auto &b:bits){
			// 这个字符串不需要幻视就是对的
			if(b==0) continue;
			if((s&b)==0){
				ok=false;
				break;
			}
		}
		if(ok){
			ans=lans;
		}
	}
	cout<<ans<<"\n";
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	
	cin>>lT;
	while(lT--)
		__();
	return 0;
}
/*
1
2
aa
1 1 8 3 4 4 8 4 2 4 6 8 9 8 2 2 8
2

ans:0

1
4
abbc
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
4

ans:0
AC
https://acm.hdu.edu.cn/contest/view-code?cid=1172&rid=25007
*/
```


:::


## 心路历程（WA，TLE，MLE……）