hdu 4426 Palindromic Substring 字符串hash

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;
const int maxn=4e5+9,maxm=11371111;;
const long long mod=777777777;
char a[maxn];
int dp[maxn];
unsigned long long sum[maxn],pow[maxn];
int n,m;
int score[maxn];
int hash[maxm],lon;
struct D
{
int next,pos,size;
long long sum;
unsigned long long _key;
long long key;
bool operator <(const D & xx) const
{
return key<xx.key;
}
}data[maxn];

void getpal()
{
int top=0;
dp[0]=0,a[0]=-1,a[n+1]=-2;
for(int i=1,t,s;i<=n;i++)
{
if(top+dp[top]<i)
{
top=i;
t=i-1,s=i+1;
while(a[t]==a[s]) t--,s++;
dp[i]=s-i-1;
}
else
{
if(dp[top-(i-top)]+i<top+dp[top])
dp[i]=dp[top-(i-top)];
else
{
s=top+dp[top]+1;
t=i-(s-i);
while(a[t]==a[s]) t--,s++;
dp[i]=s-i-1;
top=i;
}
}
}
}

bool insert(int pos,int size,long long ff)
{
if(a[pos]=='#') pos++;

unsigned long long _key=(sum[pos+(size-1)*2]-sum[pos-2]);
_key*=pow[n-pos];
int key=_key%maxm;
for(int k=hash[key];k!=-1;k=data[k].next)
{
if(data[k]._key==_key)
{
data[k].sum+=ff;
return false;
}
}
data[++lon].sum=ff;
data[lon].pos=pos;
data[lon].size=size;
data[lon]._key=_key;
data[lon].next=hash[key];
hash[key]=lon;
return true;
}

void getkey()
{
sum[0]=0;
for(int i=2;i<=n;i+=2)
{
sum[i]=sum[i-2];
sum[i]+=(a[i]-'a'+1)*pow[i];
}
}

struct R
{
int t,key;
bool operator <(const R & xx) const
{
return key<xx.key;
}
};

void gethash()
{
memset(hash,-1,sizeof(hash));
lon=0;
getkey();
for(int i=1;i<=n;i++)
if(dp[i]>0)
insert(i,dp[i]+1>>1,1);

priority_queue <R> q;
while(!q.empty()) q.pop();
for(int i=1;i<=lon;i++)
{
R now;
now.key=data[i].size;
now.t=i;
q.push(now);
}
while(!q.empty())
{
int pos=data[q.top().t].pos;
int size=data[q.top().t].size;
long long ff=data[q.top().t].sum;
size--;
q.pop();
if(size&&insert(pos,size,ff))
{
R now;
now.t=lon;
now.key=size;
q.push(now);
}
}
}
long long nn[maxn],pp[maxn];
void getkey(int t)
{
data[t].key=nn[data[t].pos];
int ff=data[t].pos+data[t].size*2;
if(ff>n) return ;
long long tmp=(nn[ff]*pp[data[t].size])%mod;
data[t].key=((data[t].key+mod-tmp))%mod;

}

void getnow()
{
pp[0]=1;
for(int i=1;i<=n+1;i++)
{
pp[i]=(pp[i-1]*26)%mod;
}
nn[n+1]=0;
for(int i=n-1;i>=1;i-=2)
{
nn[i]=(nn[i+2]*26)%mod;
nn[i]=(nn[i]+score[(a[i]-'a'+1)])%mod;
}
}

void solve(long long num)
{
getnow();
for(int i=1;i<=lon;i++)
getkey(i);
sort(data+1,data+1+lon);
long long now=0;
for(int i=1;i<=lon;i++)
{
now+=data[i].sum;
if(now>=num)
{
printf("%I64d\n",data[i].key);
break;
}
}
if(now<num)
printf("0\n");
}

int main()
{
pow[0]=1;
for(int i=1;i<maxn;i++)
pow[i]=pow[i-1]*27;

//    freopen("in.txt","r",stdin);
//    freopen("out.txt","w",stdout);
int T;
scanf("%d",&T);
while(T--)
{
scanf("%d%d",&n,&m);
scanf("%s",a+1);
for(int i=n;i>=1;i--)
{
a[i*2]=a[i];
a[i*2-1]='#';
}
n<<=1;
a[++n]='#';
getpal();

gethash();

for(int i=1;i<=m;i++)
{
long long tmp;
scanf("%I64d",&tmp);
for(int j=1;j<=26;j++)
scanf("%d",&score[j]);
solve(tmp);
}
cout<<endl;
}
return 0;
}