BZOJ 2806 [Ctsc2012]Cheat ——后缀自动机 单调队列优化DP

#include <map>
#include <ctime>
#include <cmath>
#include <queue>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
#define F(i,j,k) for (int i=j;i<=k;++i)
#define D(i,j,k) for (int i=j;i>=k;--i)
#define maxn 2200005
 
namespace SAM{
    int last,cnt,go[maxn][2],l[maxn],fa[maxn],n,m,q;
    int f[maxn],que[maxn],hd,tl,d[maxn];
    char s[maxn];
    void init(){last=cnt=1;}
    void add(int x)
    {
        int q,p=last;
        if (q=go[p][x])
        {
            if (l[q]==l[p]+1) last=q;
            else
            {
                int nq=last=++cnt;
                l[nq]=l[p]+1;
                memcpy(go[nq],go[q],sizeof go[q]);
                fa[nq]=fa[q];fa[q]=nq;
                for (;go[p][x]==q&&p;p=fa[p]) go[p][x]=nq;
                last=nq;
            }
        }
        else
        {
            int np=last=++cnt; l[np]=l[p]+1;
            for (;p&&!go[p][x];p=fa[p]) go[p][x]=np;
            if (!p) fa[np]=1;
            else
            {
                q=go[p][x];
                if (l[q]==l[p]+1) fa[np]=q;
                else
                {
                    int nq=++cnt;l[nq]=l[p]+1;
                    memcpy(go[nq],go[q],sizeof go[q]);
                    fa[nq]=fa[q];
                    fa[q]=fa[np]=nq;
                    for (;p&&go[p][x]==q;p=fa[p]) go[p][x]=nq;
                }
            }
        }
    }
    void ins()
    {
        last=1;
        scanf("%s",s+1); n=strlen(s+1);
        F(i,1,n) add(s[i]-‘0‘);
    }
    bool check(int mid)
    {
        f[0]=0; tl=0;hd=1;
        F(i,1,n)
        {
            f[i]=f[i-1];int p=i-mid;
            if (p>=0)
            {
                while (hd<=tl&&f[que[tl]]-que[tl]<f[i-mid]-p)tl--;
                que[++tl]=p;
            }
            while (hd<=tl&&que[hd]<i-d[i]) hd++;
            if (hd<=tl) f[i]=max(f[i],f[que[hd]]+i-que[hd]);
        }
        if (f[n]*10>=n*9) return true;
        else return false;
    }
    void dp()
    {
        scanf("%s",s+1); n=strlen(s+1);
        memset(d,0,(n+1)*sizeof(int));
        int now=1,t=0;
        F(i,1,n)
        {
            if (go[now][s[i]-‘0‘])
                now=go[now][s[i]-‘0‘],t++;
            else
            {
                while (now&&!go[now][s[i]-‘0‘]) now=fa[now];
                if (!now) now=1,t=0;
                else t=l[now]+1,now=go[now][s[i]-‘0‘];
            }
            d[i]=t;
        }
        int l=0,r=n;
        while (l<r)
        {
            int mid=(l+r)/2+1;
            if (check(mid)) l=mid;
            else r=mid-1;
        }
        printf("%d\n",l);
    }
    void solve()
    {
        init();
        scanf("%d%d",&q,&m);
        F(i,1,m) ins();
        F(i,1,q) dp();
    }
}
 
int main()
{
    using namespace SAM;
    solve();
}