hdu3068最长回文 后缀数组TLE版本23333

感觉学习了后缀数组整个人都好了,于是看到这题想都没想就开始写,然而事实并不如意,TTTTTTTTQAQQQQQQ,赶快吧O复杂度换成T复杂度,真是玄学4亿多= =

放下个TLE的版本,还有就是被之前学的版本坑了,在原串和反串之间加入了特殊符号之后,height数组的最大值就已经是答案了

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<algorithm>
#define LL long long
#define fo(i,a,b) for(int i=a;i<=b;i++)
#define down(i,a,b) for(int i=a;i>=b;i--)
using namespace std;
#define N 220005
#define M 30
char s[N];
int sa[N],height[N],ra[N];
int n,ans;

int C[N];
void getsa(int m)
{
	fo(i,0,n)ra[i]=0,sa[i]=0,height[i]=0;
	fo(i,0,m)C[i]=0;
	fo(i,1,n)ra[i]=s[i]-96,C[ra[i]]++;
	fo(i,1,m)C[i]+=C[i-1];
//	cout<<n<<' '<<ra[n]<<' '<<C[ra[n]]<<' '<<sa[C[ra[n]]]<<endl;
	down(i,n,1)sa[C[ra[i]]--]=i;
	for(int k=1;k<=n;k<<=1)
	{
		int p=0;
		fo(i,n-k+1,n)height[++p]=i;
		fo(i,1,n)if(sa[i]>k)height[++p]=sa[i]-k;
		fo(i,0,m)C[i]=0;
		fo(i,1,n)C[ra[height[i]]]++;
		fo(i,1,m)C[i]+=C[i-1];
		down(i,n,1)sa[C[ra[height[i]]]--]=height[i];
		
		swap(ra,height);p=0;ra[sa[1]]=++p;
		fo(i,2,n)
		if(height[sa[i]]==height[sa[i-1]]&&height[sa[i]+k]==height[sa[i-1]+k])
		ra[sa[i]]=p;else ra[sa[i]]=++p;//cout<<"Run:"<<k<<endl;
		if(n==p)break;
		m=p;
	}
//	fo(i,1,n)fo(j,sa[i],n)cout<<s[j];cout<<endl;
}
		
void getheight()
{
	int i=0,j=0,k=0;
	for(i=1;i<=n;height[ra[i++]]=k,ans=max(ans,k))
	for(k?k--:0,j=sa[ra[i]-1];s[i+k]==s[j+k];k++);
//	fo(i,1,n)cout<<height[i]<<' ';cout<<endl;
}

int main()
{
	while(scanf("%s",s+1)!=EOF)
	{
		n=strlen(s+1);int len=n;s[n+1]='z'+1;ans=0;
		for(int i=1,j=2*n+1;i<j;i++,j--)s[j]=s[i];n<<=1;n++;
		getsa(27);
		getheight();
//		fo(i,2,n)ans=max(height[i],ans);
		printf("%d\n",ans);
	}
	return 0;
}


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