洛谷 P1063 能量项链

题目传送门

解题思路：

一道很模板的环形dp,要注意状态转移时串的头和尾到底是哪个.

AC代码:

 1 #include<cstdio>
 2 #include<iostream>
 3 
 4 using namespace std;
 5 
 6 int n,a[202],f[202][202],ans;
 7 
 8 int main()
 9 {
10     scanf("%d",&n);
11     for(int i = 1;i <= n; i++){
12          scanf("%d",&a[i]);
13          a[i+n] = a[i];
14     }
15     for(int p = 1;p < n; p++)
16          for(int i = 1,j = i + p;i < n + n && j <= n + n; i++,j = i + p)
17             for(int k = i;k < j; k++)
18                 f[i][j] = max(f[i][j],f[i][k] + f[k+1][j] + a[i] * a[k+1] * a[j+1]);
19     for(int i = 1;i <= n; i++)
20         ans = max(ans,f[i][i+n-1]);
21     printf("%d",ans);
22     return 0;
23 }

 

转载于:https://www.cnblogs.com/lipeiyi520/p/11587278.html