spoj SUBST1 - New Distinct Substrings(后缀数组)

题目连接

题意：求所有不同的子串个数。

思路：后缀数组。和上一道题一样，就是数据范围变成了 5E4...1A

/* ***********************************************
Author :111qqz
Created Time :2016年08月02日 星期二 18时32分28秒
File Name :code/spoj/subst1.cpp
************************************************ */
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <cmath>
#include <cstdlib>
#include <ctime>
#define fst first
#define sec second
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define ms(a,x) memset(a,x,sizeof(a))
typedef long long LL;
#define pi pair < int ,int >
#define MP make_pair
using namespace std;
const double eps = 1E-8;
const int dx4[4]={1,0,0,-1};
const int dy4[4]={0,-1,1,0};
const int inf = 0x3f3f3f3f;
const int  N=5E4+7; 
char s[N];
int sa[N],rk[N],t[N],t2[N],cnt[N],height[N];
int cmp (int *r,int a,int b,int l){ return r[a]==r[b]&&r[a+l]==r[b+l];}
void getSa(int n,int m)
{
    int *x=t,*y=t2;
    ms(cnt,0);
    for ( int i = 0 ; i < n ; i++) cnt[x[i]=s[i]]++;
    for ( int i = 0 ; i < m ; i++) cnt[i]+=cnt[i-1];
    for ( int i = n-1 ; i >= 0 ; i--) sa[--cnt[x[i]]] = i;
    for ( int k = 1 ; k <= n ; k<<=1)
    {
	int p = 0;
	for ( int i = n-k ; i < n ; i++) y[p++] = i;
	for ( int i = 0 ; i < n;  i++) if (sa[i]>=k) y[p++] = sa[i]-k;
	ms(cnt,0);
	for ( int i = 0 ; i <n ; i++) cnt[x[y[i]]]++;
	for ( int i = 0 ;i < m ; i++) cnt[i]+=cnt[i-1];
	for ( int i = n-1 ; i >= 0 ; i--) sa[--cnt[x[y[i]]]] = y[i];
	swap(x,y);
	p = 1;
	x[sa[0]] = 0;
	for ( int i = 1 ; i < n ; i++ )
	    x[sa[i]] = cmp(y,sa[i-1],sa[i],k)?p-1:p++;
	if (p>=n) break;
	m = p;
    }
}
void getHeight( int n)
{
    int k = 0 ;
    for ( int i = 0 ; i <n ; i ++) rk[sa[i]] = i ;
    height[0] = 0 ;
    for ( int i = 0 ; i < n ; i++)
    {
	if (rk[i]==0) continue;
	if (k) k--;
	int j = sa[rk[i]-1];
	while (s[i+k]==s[j+k]) k++;
	height[rk[i]] = k;
    }
}
int getSuffix(char s[])
{
    int len = strlen(s);
    int up = 0 ;
    for ( int i = 0 ; i < len ; i++)
    {
	int val = s[i];
	up = max(up,val);
    }
    s[len++]='$';
    getSa(len,up+1);
    getHeight(len);
    return len;
}
int solve ( int n)
{
    ms(cnt,0);
    int up  =  0;
    for ( int i = 0 ;i <n ; i ++) cnt[height[i]]++, up = max(up,height[i]);
    for ( int i = up-1 ; i >= 1;  i--) cnt[i]+=cnt[i+1];
    int res = 0 ;
    for ( int i = 1 ; i <=up ; i++)
	res+=cnt[i];
    return res;
}
int main()
{
	#ifndef  ONLINE_JUDGE 
	freopen("code/in.txt","r",stdin);
  #endif
	int T;
	scanf("%d",&T);
	while (T--)
	{
	    scanf("%s",s);
	    int len = getSuffix(s);
	    LL ans = 1LL*len*(len-1)/2;
	    ans-=1LL*solve(len);
	    printf("%lld\n",ans);
	}
  #ifndef ONLINE_JUDGE  
  fclose(stdin);
  #endif
    return 0;
}