题解 | #凸多边形的划分#

dp数组及输入输出需要__int128类型

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
const int N=110;
**__int128 dp[N][N];**
**__int128 a[N];**
**__int128 read()**
{
    __int128 x=0,f=1;
    char ch=getchar();
    while(ch<'0'||ch>'9')
    {
         if(ch=='-') f=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9')
    {
         x=x*10+ch-'0';
        ch=getchar();
    }
     return x*f;
}
void write(__int128 x)
{
    if(x<0)
    {
         putchar('-');
        x=-x;
    }
    if(x>9) 
        write(x/10);
    putchar(x%10+'0');
}
int n;

void solve()
{
	for (int len = 3; len <= n; len++)//区间长度
	{
		for (int l = 1; l + len - 1 <= n; l++)//区间起点
		{
			int r = l + len - 1;//区间终点
			dp[l][r] = 1e30;
			for (int k = l + 1; k < r; k++)
			{
				dp[l][r] = min(dp[l][r], dp[l][k] + dp[k][r] + a[l] * a[k] * a[r]);
			}
		}
	}
	write(dp[1][n]);
}

int main()
{
	cin >> n;
	for (int i = 1; i <= n; i++)
	{
		a[i]=read();
	}
	solve();
	return 0;
}