BZOJ 1044 木棍分割

二分+dp.

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define maxn 50050
#define mod 10007
using namespace std;
int n,m,l[maxn],len,sums=,lb[maxn],dp[maxn][],sum[maxn][],mx=,ans=;
bool check(int len)
{
    int now=l[],ret=;
    for (int i=;i<=n;i++)
    {
        if (now+l[i]>len)     {ret++;now=l[i];}
        else now+=l[i];
    }
    return ret<=m;
}
void binary_search()
{
    int l=mx,r=sums;
    while (l<=r)
    {
        int mid=(l+r)>>;
        if (check(mid)) {len=mid;r=mid-;}
        else l=mid+;
    }
}
void get_bnd()
{
    int ret=,now=;
    for (int i=;i<=n;i++)
    {
        ret-=l[i-];
        while ((ret+l[now+]<=len) && (now+<=n))
        {
            now++;ret+=l[now];
            lb[now]=i;
        }
    }
}
void dps()
{
    for (int i=;i<=n;i++) if (lb[i]==) dp[i][]=;
    for (int i=;i<=n;i++) sum[i][]=sum[i-][]+dp[i][];
    ans+=dp[n][];
    for (int i=;i<=m;i++)
    {
        for (int j=;j<=n;j++)
        {
            if (j<=i) {dp[j][i&]=sum[j][i&]=;continue;}
            if (lb[j]-) dp[j][i&]=(sum[j-][(i&)^]-sum[lb[j]-][(i&)^]+mod)%mod;
            else dp[j][i&]=sum[j-][(i&)^]%mod;
            sum[j][i&]=(sum[j-][i&]+dp[j][i&])%mod;
        }
        ans=(ans+dp[n][i&])%mod;
    }
}
int main()
{
    scanf("%d%d",&n,&m);
    for (int i=;i<=n;i++) {scanf("%d",&l[i]);sums+=l[i];mx=max(mx,l[i]);}
    binary_search();
    get_bnd();
    dps();
    printf("%d %d\n",len,ans);
    return ;
}