Good Article Good sentence HDOJ4416

做了这题，不得不说对后缀数组的理解还是不深刻（感觉这题SAM也可以搞，等学透了SAM再来看看这题），题意就是求第一个串S1中有多少个子串不是其他串Si(i > 1)的子串，老规矩，先把串都连接起来，中间用不同的字符连接起来， 然后求每个S1的后缀与其他串Si的后缀的lcp，这表明该后缀有lcp的子串是其他串的子串，这里求lcp不用把每个S1的后缀与Si的后缀求lcp，根据后缀数组的性质，只要从左右两边扫描一遍即可(具体见代码)，最后排除掉S1串中本身重复的子串， 还要注意的是此题有n=0的时候， WA到吐。

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <queue>
#include <algorithm>
#include <vector>
#include <cstring>
#include <stack>
#include <cctype>
#include <utility>   
#include <map>
#include <string>  
#include <climits> 
#include <set>
#include <string>    
#include <sstream>
#include <utility>   
#include <ctime>
#include <bitset>

using std::priority_queue;
using std::vector;
using std::swap;
using std::stack;
using std::sort;
using std::max;
using std::min;
using std::pair;
using std::map;
using std::string;
using std::cin;
using std::cout;
using std::set;
using std::queue;
using std::string;
using std::stringstream;
using std::make_pair;
using std::getline;
using std::greater;
using std::endl;
using std::multimap;
using std::deque;
using std::unique;
using std::lower_bound;
using std::random_shuffle;
using std::bitset;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PAIR;
typedef multimap<int, int> MMAP;
typedef LL TY;

const int MAXN(300010);
const int MAXM(50010);
const int MAXE(100010);
const int MAXK(6);
const int HSIZE(131313);
const int SIGMA_SIZE(52);
const int MAXH(19);
const int INFI((INT_MAX-1) >> 1);
const ULL BASE(31);
const LL LIM(10000000);
const int INV(-10000);
const int MOD(1000000007);
const double EPS(1e-7);

template<typename T> void checkmax(T &a, T b){if(b > a) a = b;}
template<typename T> void checkmin(T &a, T b){if(b < a) a = b;}
template<typename T> T ABS(const T &a){return a < 0? -a: a;}

char str[100010];

struct SA
{
	int S[MAXN];
	int sa[MAXN], t1[MAXN], t2[MAXN], cnt[MAXN], len, M;
	void init(int tl, int tm = 128)
	{
		len = tl;
		M = tm;
		int *p1 = t1;
		int *p2 = t2;
		for(int i = 0; i < M; ++i) cnt[i] = 0;
		for(int i = 0; i <= len; ++i) ++cnt[p1[i] = S[i]];
		for(int i = 1; i < M; ++i) cnt[i] += cnt[i-1];
		for(int i = len; i >= 0; --i) sa[--cnt[p1[i]]] = i;
		int temp = 1;
		for(int k = 1; temp <= len; k <<= 1)
		{
			temp = 0;
			for(int i = len-k+1; i <= len; ++i) p2[temp++] = i;
			for(int i = 0; i <= len; ++i)
				if(sa[i] >= k)
					p2[temp++] = sa[i]-k;
			for(int i = 0; i < M; ++i) cnt[i] = 0;
			for(int i = 0; i <= len; ++i) ++cnt[p1[p2[i]]];
			for(int i = 1; i < M; ++i) cnt[i] += cnt[i-1];
			for(int i = len; i >= 0; --i) sa[--cnt[p1[p2[i]]]] = p2[i];
			swap(p1, p2);
			temp = 1;
			p1[sa[0]] = 0;
			for(int i = 1; i <= len; ++i)
				p1[sa[i]] = p2[sa[i-1]] == p2[sa[i]] && p2[sa[i-1]+k] == p2[sa[i]+k]? temp-1: temp++;
			M = temp;
		}
	}
	int rank[MAXN], height[MAXN];
	void getHeight()
	{
		int k = 0;
		for(int i = 0; i <= len; ++i)
			rank[sa[i]] = i;
		for(int i = 0; i < len; ++i)
		{
			if(k) --k;
			int j = sa[rank[i]-1];
			while(S[i+k] == S[j+k]) ++k;
			height[rank[i]] = k;
		}
	}
	/*
	int Log[MAXN];
	int table[MAXH][MAXN];
	void initLog()
	{
		Log[0] = -1;
		for(int i = 1; i < MAXN; ++i)
			Log[i] = (i&(i-1))?Log[i-1]: Log[i-1]+1;
	}
	void initRMQ()
	{
		for(int i = 1; i <= len; ++i)
			table[0][i] = height[i];
		for(int i = 1; (1 << i) <= len; ++i)
			for(int j = 1; j+(1 << i)-1 <= len; ++j)
				table[i][j] = min(table[i-1][j], table[i-1][j+(1 << (i-1))]);
	}
	int lcp(int a, int b)
	{
		a = rank[a];
		b = rank[b];
		if(a > b) swap(a, b);
		++a;
		int temp = Log[b-a+1];
		return min(table[temp][a], table[temp][b-(1 << temp)+1]);
	}
	*/
}sa;

int len1, len2;
int rec[MAXN];

int main()
{
	int TC, n_case(0);
	scanf("%d", &TC);
	while(TC--)
	{
		int n;
		scanf("%d", &n);
		scanf("%s", str);
		len2 = len1 = strlen(str);
		for(int i = 0; i <= len1; ++i)
			sa.S[i] = str[i];
		int temp = 'z'+1;
		for(int i = 0; i < n; ++i)
		{
			scanf("%s", str);
			sa.S[len2++] = temp++;
			int tlen = strlen(str);
			for(int j = 0; j <= tlen; ++j)
				sa.S[len2+j] = str[j];
			len2 += tlen;
		}
		sa.init(len2, temp);
		sa.getHeight();
		printf("Case %d: ", ++n_case);
		LL ans;
		ans = (LL)len1*(len1+1)/2;
		if(n == 0)
		{
			for(int i = 1; i <= len1; ++i)
				ans -= sa.height[i];
			printf("%I64d\n", ans);
			continue;
		}
		temp = INFI;
		for(int i = 1; i <= len2; ++i)
			if(sa.sa[i] <= len1)
			{
				checkmin(temp, sa.height[i]);
				rec[i] = temp;
			}
			else
				temp = INFI;
		temp = INFI;
		for(int i = len2; i >= 1; --i)
			if(sa.sa[i-1] <= len1)
			{
				checkmin(temp, sa.height[i]);
				checkmax(rec[i-1], temp);
			}
			else
				temp = INFI;
		for(int i = 0; i < len1; ++i)
			if(sa.sa[sa.rank[i]-1] <= len1)
				checkmax(rec[sa.rank[i]], sa.height[sa.rank[i]]);
		for(int i = 0; i < len1; ++i)
			ans -= rec[sa.rank[i]];
		printf("%I64d\n", ans);
	}
	return 0;
}