SA是唯一听懂了怎么求的东西

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
typedef long long ll;
const int N=500005;
char s[N];
int sa[N],rank[N],height[N],cnt[N],f[N],a[N*6],sta[N],mn[N][25],log[N],num[N],n,q,m=26;
int get(int l,int r)
{
int k=log[r-l+1];
return min(mn[l][k],mn[r-(1<<k)+1][k]);
}
int main()
{
ll now,ans;
int x,p,top,tot;
scanf("%d%d",&n,&q);
scanf("%s",s+1);
for (int i=1;i<=n;i++)cnt[rank[i]=f[i]=s[i]-'a'+1]++;
for (int i=1;i<=m;i++)cnt[i]+=cnt[i-1];
for (int i=n;i;i--)sa[cnt[f[i]]--]=i;
for (int k=1;k<=n;k<<=1)
{
p=0;
for (int i=n-k+1;i<=n;i++)f[++p]=i;
for (int i=1;i<=n;i++)
if (sa[i]>k)f[++p]=sa[i]-k;
for (int i=1;i<=m;i++)cnt[i]=0;
for (int i=1;i<=n;i++)cnt[rank[f[i]]]++;
for (int i=1;i<=m;i++)cnt[i]+=cnt[i-1];
for (int i=n;i;i--)sa[cnt[rank[f[i]]]--]=f[i];
for (int i=1;i<=n;i++)f[i]=rank[i];
rank[sa[1]]=1;
for (int i=2;i<=n;i++)
if (f[sa[i]]!=f[sa[i-1]]||f[sa[i]+k]!=f[sa[i-1]+k])
rank[sa[i]]=rank[sa[i-1]]+1;
else rank[sa[i]]=rank[sa[i-1]];
m=rank[sa[n]];
if (m>=n)break;
}
for (int i=1;i<=n;i++)
{
height[rank[i]]=height[rank[i-1]];
if (height[rank[i]])height[rank[i]]--;
while (s[i+height[rank[i]]]==s[sa[rank[i]-1]+height[rank[i]]])
height[rank[i]]++;
}
for (int i=1;i<=n;i++)mn[i][0]=height[i];
for (int k=1;(1<<k)<=n;k++)log[1<<k]=k;
for (int i=3;i<=n;i++)
if (!log[i])log[i]=log[i-1];
for (int k=1;(1<<k)<=n;k++)
for (int i=1;i+(1<<k)-1<=n;i++)
mn[i][k]=min(mn[i][k-1],mn[i+(1<<k-1)][k-1]);
while (q--)
{
scanf("%d",&m);
for (int i=1;i<=m;i++)
{
scanf("%d",&x);
a[i]=rank[x];
}
sort(a+1,a+m+1);
m=unique(a+1,a+m+1)-a-1;
now=sta[top=1]=n-sa[a[1]]+1;
ans=0;
num[1]=1;
for (int i=2;i<=m;i++)
{
x=get(a[i-1]+1,a[i]);
tot=0;
while (top&&x<=sta[top])
{
now-=(ll)num[top]*sta[top];
tot+=num[top];
top--;
}
now+=(ll)x*tot;
ans+=now;
sta[++top]=x;
num[top]=tot;
sta[++top]=n-sa[a[i]]+1;
num[top]=1;
now+=sta[top];
}
printf("%lld\n",ans);
}
}

posted on 2018-02-26 14:54  宣毅鸣  阅读(107)  评论(0编辑  收藏  举报