HDU 4622 Reincarnation 后缀自动机

#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>

using namespace std;

#define N 2010
#define MAXQ 10010

struct Suffix_Automaton
{
int F[N << 1],ant,last,ch[N << 1][26],step[N << 1];

void init()
{
last = ant = 1;
memset(F,0,sizeof(F));
memset(ch,0,sizeof(ch));
memset(step,0,sizeof(step));
}

void ins(int x)
{
int t = ++ant, pa = last;
step[t] = step[last] + 1;
last = t;
for( ; pa && !ch[pa][x]; pa = F[pa] )
ch[pa][x] = t;
if( pa == 0 ) F[t] = 1;
else if( step[pa] + 1 == step[ ch[pa][x] ] )
F[t] = ch[pa][x];
else
{
int nq = ++ant, q = ch[pa][x];
memcpy( ch[nq], ch[q], sizeof(ch[nq]) );
step[nq] = step[pa] + 1;
F[nq] = F[q];
F[q] = F[t] = nq;
for( ; pa && ch[pa][x] == q; pa = F[pa] )
ch[pa][x] = nq;
}
}
};
//以上为后缀自动机模板

struct node
{
int l, r;
int id;
};

node qry[MAXQ];
char str[2010];
int ans[MAXQ];
Suffix_Automaton SAM;

bool cmp( node a, node b )
{
if ( a.l == b.l ) return a.r < b.r;
return a.l < b.l;
}

int main()
{
int T;
scanf( "%d", &T );
while ( T-- )
{
scanf( "%s", &str[1] );
int Q;
scanf( "%d", &Q );
for ( int i = 0; i < Q; ++i )
{
scanf("%d%d", &qry[i].l, &qry[i].r );
qry[i].id = i;
}
sort( qry, qry + Q, cmp );

int preL = qry[0].l;
SAM.init();
int j = preL;
for ( int i = 0; i < Q; ++i )
{
if ( qry[i].l == preL )
{
while ( j <= qry[i].r )
{
SAM.ins( str[j] - 'a' );
++j;
}
int tmp = 0;
for ( int k = SAM.ant; k > 0; --k )
tmp += SAM.step[k] - SAM.step[ SAM.F[k] ];
ans[ qry[i].id ] = tmp;
}
else
{
preL = qry[i].l;
j = qry[i].l;
SAM.init();
while ( j <= qry[i].r )
{
SAM.ins( str[j] - 'a' );
++j;
}
int tmp = 0;
for ( int k = SAM.ant; k > 0; --k )
tmp += SAM.step[k] - SAM.step[ SAM.F[k] ];
ans[ qry[i].id ] = tmp;
}
}

for ( int i = 0; i < Q; ++i )
printf( "%d\n", ans[i] );
}
return 0;
}