Hdu 4622 Reincarnation(后缀自动机）

/*
字符串长度较小， 可以离线或者直接与处理所有区间的答案 
动态加入点的时候， 因为对于其他点的parent构造要么没有影响， 要么就是在两个节点之间塞入一个点， 对于minmax的贡献没有改变
所以只统计这个点的贡献就好了 
*/
#include<cstdio>
#include<algorithm>
#include<iostream>
#include<cstring>
#include<queue>
#define ll long long 
#define M 4040
#define mmp make_pair
using namespace std;
int read()
{
	int nm = 0, f = 1;
	char c = getchar();
	for(; !isdigit(c); c = getchar()) if(c == '-') f = -1;
	for(; isdigit(c); c = getchar()) nm = nm * 10 + c - '0';
	return nm * f;
}

int len[M], fa[M], ch[M][26], lst, cnt;
int ans[2020][2020];
char s[M];

void init()
{
	memset(len, 0, sizeof(len));
	memset(ch, 0, sizeof(ch));
	memset(fa, 0, sizeof(fa));
	lst = cnt = 1;
}

void insert(int c)
{
	int p = ++cnt, f = lst;
	lst = p;
	len[p] = len[f] + 1;
	while(f && !ch[f][c]) ch[f][c] = p, f = fa[f];
	if(!f) fa[p] = 1;
	else
	{
		int q = ch[f][c];
		if(len[q] == len[f] + 1) fa[p] = q;
		else
		{
			int nq = ++cnt;
			fa[nq] = fa[q];
			memcpy(ch[nq], ch[q], sizeof(ch[nq]));
			len[nq] = len[f] + 1;
			fa[p] = fa[q] = nq;
			while(f && ch[f][c] == q) ch[f][c] = nq, f = fa[f];
		}
	}
}
int main()
{
	int t = read();
	while(t--)
	{
		//Init();
		scanf("%s", s + 1);
		int n = strlen(s + 1);
		for(int i = 1; i <= n; i++)
		{
			init();
			for(int j = i; j <= n; j++) insert(s[j] - 'a'), ans[i][j] = ans[i][j - 1] + len[lst] - len[fa[lst]];
		}
		int q = read();
		while(q--)
		{
			int l = read(), r = read();
			cout << ans[l][r] << "\n";
		}
	}
	return 0;
}