AW282 石子合并

题目地址

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易错点：

• 要清楚动态规划的基本概念和应对方式.
• 原题有环，处理环的话需要断开接一倍.

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#include<cstdio>
#include<iostream>
#include<cstring>
using namespace std;
const int MAXN=350;
int f[MAXN][MAXN],sum[MAXN],a[MAXN];
int main(){
	memset(f,0x3f,sizeof(f));
	int n;
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		int tmp;
		scanf("%d",&tmp);
		a[i]=tmp;
		sum[i]+=sum[i-1]+tmp;
		f[i][i]=0;
	}
	for(int len=2;len<=n;len++){
		for(int l=1;l<=n-len+1;l++){
			int r=l+len-1;
			for(int k=l;k<r;k++){
				f[l][r]=min(f[l][r],f[l][k]+f[k+1][r]+sum[r]-sum[l-1]);
			}
		}
	}
	printf("%d\n",f[1][n]);
	return 0;
}