对着第一篇题解调了一下午也没搞定

本蒟蒻自觉已经把题解中的剪枝全加上了

最后一个点271ms淦

#include<cstdio>
#include<algorithm>
#include <cstdlib>
#include<iostream>
#include<cstring>
#include<cmath>
#include<ratio>
#include<shared_mutex>
#include<utility>
#include<vector>
#include<queue>
#include<bitset>
#include<iostream>
#include<queue>
#include<stack>
#include<ctime>
#include<list>
using namespace std;
#define lowbit(x) x&(-x)
int n;
int Lenth[70],tot;
int sum,MMn;
bool CMP(int a,int b) {return a>b;}
bool isUse[70];
int N;
int bound(int val)
{
	int l=1,r=tot;
	int mid;
	while (l<r)
	{
		mid=(l+r)/2;
		if (Lenth[mid]>val) l=mid+1;
		else r=mid;
	}
	return l;
}
int tree[70];
inline void update_point(int pos,int date)
{
	while(pos<=n)
	{
		tree[pos]+=date;
		pos+=lowbit(pos);
	}
}
inline int query_sum(int x)
{
	int res=0;
	while(x)
	{
		res+=tree[x];
		x-=lowbit(x);
	}
	return res;
}
int Next[70];
bool dfs(int target/*目标长度*/,int restR/*当前在拼的木棍距离目标剩余长度*/,
		 int restStick/*剩的棍子*/,int sumSuccess/*已经拼成的*/,
		 int last/*上次拼的长度*/,int lastpos/*上一根的位置*/)
{
	if (sumSuccess==N) return true;
	for (int i=max(bound(restR),lastpos?lastpos:bound(last));i<=tot;i++)
	{
		if (isUse[i]) continue;
		if (restR==Lenth[i])
		{
			isUse[i]=1;
			if (dfs(target,target,restStick-1,sumSuccess+1,target,0))
				return true;
			isUse[i]=0;
			return false;
		}
		if (query_sum(tot)-query_sum(i-1)<restR) return false;
		update_point(i,-Lenth[i]);
		isUse[i]=1;
		if (dfs(target,restR-Lenth[i],restStick-1,sumSuccess,Lenth[i],i+1))
			return true;
		isUse[i]=0;
		update_point(i,Lenth[i]);
		if (restR==target) return false;
		i=Next[i];
	}
	return false;
}
int main()
{
	scanf("%d",&n);
	for (int i=1,x;i<=n;i++)
	{
		scanf("%d",&x);
		if (x>50) continue;
		Lenth[++tot]=x;
		sum+=x;
		MMn=max(MMn,x);
	}
	sort(Lenth+1,Lenth+1+tot,CMP);
	for (int i=tot;i>=1;i--)
		update_point(i,Lenth[i]);
	Next[tot]=tot;
	for (int i=tot-1;i>=1;i--)
		if (Lenth[i]==Lenth[i+1]) Next[i]=Next[i+1];
		else Next[i]=i;
	for (int i=MMn;i<=sum;i++)
	{
		if (sum%i) continue;
		N=sum/i;
		if (dfs(i,i,tot,0,i,0))
		{
			printf("%d",i);
			return 0;
		}
	}
	return 0;
}
···