ch 5e09 区间dp

区间dp模板

#include <cstdio>
#include <iostream>
#include <iomanip>
#include <string>
#include <cstdlib>
#include <cstring>
#include <queue>
#include <set>
#include <vector>
#include <map>
#include <algorithm>
#include <cmath>
#include <stack>

#define INF 0x3f3f3f3f
#define IMAX 2147483646
#define LINF 0x3f3f3f3f3f3f3f3f
#define ll long long
#define ull unsigned long long
#define uint unsigned int

using namespace::std;

ll a[222], f[222][222],n;

int main() {
	scanf("%lld", &n);
	for (int i = 1; i <= n; i++) scanf("%lld", &a[i]);;
	for (int i = n + 1; i <= n * 2; i++) a[i] = a[i - n];
	for (int len = 3; len <= n + 1; len++)
		for (int l = 1; l + len - 1 <= n * 2; l++) {
			int r = l + len - 1;
			for (int k = l + 1; k < r; k++)
				f[l][r] = max(f[l][r], f[l][k] + f[k][r] + a[l] * a[k] * a[r]);
		}
	ll ans = 0;
	for (int i = 1; i <= n; i++)
		ans = max(ans, f[i][i + n]);
	printf("%lld\n", ans);
	return 0;
}