思路：区间dp + 记忆化搜索

转移方程看上一篇博客。

代码：

#pragma GCC optimize(2)#pragma GCC optimize(3)#pragma GCC optimize(4)#include
     
      using namespace std;#define fi first#define se second#define y1 y11#define pi acos(-1.0)#define LL long long//#define mp make_pair#define DEBUG#define pb push_back#define ls rt<<1, l, m#define rs rt<<1|1, m+1, r#define ULL unsigned LL#define pll pair
      
       #define pli pair
       
        #define pii pair
        
         #define piii pair
         
          #define pdd pair
          
           #define mem(a, b) memset(a, b, sizeof(a))#define fio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);#define fopen freopen("in.txt", "r", stdin);freopen("out.txt", "w", stout);//headconst int N = 105;LL dp[N][N][N];string s;int a[N];LL dfs(int l, int r, int k) { if(l > r) return 0; if(l == r) return a[k+1]; if(~dp[l][r][k]) return dp[l][r][k]; dp[l][r][k] = dfs(l, r-1, 0) + a[k+1]; for (int i = l; i < r; i++) { if(s[i] == s[r]) { dp[l][r][k] = max(dp[l][r][k], dfs(i+1, r-1, 0) + dfs(l, i, k+1)); } } return dp[l][r][k];}int main() { fio; int n; cin >> n; cin >> s; for (int i = 1; i <= n; ++i) cin >> a[i]; mem(dp, -1); cout << dfs(0, n-1, 0) << endl; return 0;}