3002 石子归并 3

#include<cstdio>
#include<cstring>
#define min(a,b) a>b?b:a
using namespace std;
#define N 3010
int n,s[N],f[N][N],b[N][N];
int main(){
	scanf("%d",&n);
	for(int i=1;i<=n;i++) scanf("%d",&s[i]),s[i]+=s[i-1];
	for(int i=1;i<=n;i++) b[i][i]=i;
	for(int j=2;j<=n;j++){
		for(int i=j-1;i>=1&&j-i+1<=n;i--){
			f[i][j]=0x7fffffff;
			for(int k=b[i][j-1];k<=b[i+1][j];k++){
				if(f[i][j]>f[i][k]+f[k+1][j]+s[j]-s[i-1]){
					f[i][j]=f[i][k]+f[k+1][j]+s[j]-s[i-1];
					b[i][j]=k;
				}
			}
		}
	}
	printf("%d\n",f[1][n]);
	return 0;
}